Class 9 · Maths · Chapter 3 · बिहार बोर्ड (BSEB)CBSE · NCERT 2026-27

Coordinate Geometry

Coordinate Geometry

How to use this page:
1. Read — Activity 1 seating · Exercise 3.1 · Cartesian plane · Exercise 3.2 · plotting · Activity 2 dice · Exercise 3.3, diagram, worked example, board tip
2. Check — each lesson has its own questions; the number follows the lesson
3. Mastery ★ — all of that lesson correct. Redo the wrong ones
4. The memory figure shows the signs of the four quadrants — first (+, +), second (−, +), third (−, −) and fourth (+, −).

In the 15-chapter Bihar book this is chapter 3. Ganita Manjari 2026-27 uses a different order. Progress stays in this browser.

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  • 1 Two facts and a seating plan — Activity 1
  • 2 The Cartesian plane and the four quadrants
  • 3 Abscissa, ordinate, and points on the axes
  • 4 Plotting a point when the coordinates are given
  • 5 The dice game — Activity 2
  • 6 The distance between two plotted points
  • Chapter winner — every lesson at mastery ★

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1

Two facts and a seating plan — Activity 1

दो सूचनाएँ और बैठक योजना — क्रियाकलाप 1 · Textbook 3.1 · Activity 1 · Exercise 3.1

New
Two facts and a seating planxyIIIIIIIV
The horizontal axis is x, the vertical is y. The signs change in the four quadrants.
One reference is not enoughNotes

A street number without a house number does not find the house. A dot on paper is not fixed by saying “it is near the top”. A place in a plane needs two independent facts — two distances from two fixed lines.

Descartes brought the idea of latitude and longitude onto a plane. That is why the method is called Cartesian. The chapter starts here, not with a formula.

Activity 1 — the seating planActivity

Push the desks together and draw the classroom. Let each desk be a square and write the name of the student in it. The place is two facts: which column, and which row.

Write the fifth column and the third row as (5, 3). Column first, then row. (3, 5) is not that seat. If Sonia sits in the fourth column and the first row, write S(4, 1). The teacher desk is not part of the plan. The teacher is only an observer.

Worked exampleExample

Question: In Exercise 3.1, how many crossings can be called (4, 3)? The scale is 1 cm = 200 m.

Answer: The street in one direction and the street in the other meet at one crossing. (4, 3) is exactly one crossing. (3, 4) is a different crossing. The order is part of the name, so do not count them as one.

10-second revision
  • A plane needs two facts
  • Activity 1: column first, then row
  • (5, 3) and (3, 5) are different desks
Board tip · BSEBBoard tip

In Exercise 3.1 both (4, 3) and (3, 4) have the answer 1. When a map is drawn, keep the scale 1 cm = 200 m.

Board tip · CBSEBoard tip

The Cartesian name comes from Descartes. If the paper asks for the name of the system, write Cartesian, not only “graph”.

Check your understandingall correct = mastery ★
1
In Activity 1, (5, 3) means —
Check
2
In the seating plan, (5, 3) and (3, 5) are the same seat.
Check
3
In Activity 1 the teacher is treated as an ______ of the plan.
Check
4
How many distances are needed at least to fix a dot on paper?
Check
5
How would you describe the position of a lamp on your table to another person? Write two measurements.
Check2 marks
Next lesson →
2

The Cartesian plane and the four quadrants

कार्तीय तल और चार चतुर्थांश · Textbook 3.2 · axes · signs

New
Two number lines crossNotes

On a number line, positive counts go to the right of the origin and negative counts to the left. Take two such lines. The horizontal line X′X is the x-axis and the vertical line Y′Y is the y-axis. They cross at their zeros. The crossing is the origin O. OX and OY are the positive directions. OX′ and OY′ are the negative directions.

The axes divide the plane into four parts. These are the quadrants, counted I, II, III, IV anticlockwise from OX. The whole plane is the axes together with these four parts. It is called the Cartesian plane, the coordinate plane, or the xy-plane.

QuadrantSignsEnclosed by
First(+, +)Positive x and positive y
Second(−, +)Negative x and positive y
Third(−, −)Negative x and negative y
Fourth(+, −)Positive x and negative y
The axes split four signs, anticlockwiseXX′YY′O (0, 0)(+, +)First(−, +)Second(−, −)Third(+, −)Fourth
Memory figure: first (+, +), second (−, +), third (−, −), fourth (+, −). The count starts at OX and goes anticlockwise.
Worked exampleExample

Question: In which quadrant is the point (−3, 4)?

Answer: x = −3 is negative and y = 4 is positive. The signs (−, +) belong to the second quadrant. The point is to the left of the y-axis and above the x-axis.

10-second revision
  • x-axis horizontal, y-axis vertical
  • The origin is the zero of both axes
  • Quadrants anticlockwise: (+,+), (−,+), (−,−), (+,−)
Board tip · BSEBBoard tip

The signs of the second and the fourth quadrant are often swapped. Negative x and positive y is the second. Positive x and negative y is the fourth.

Board tip · CBSEBoard tip

Do not write the count as clockwise. The book counts I, II, III, IV anticlockwise from OX.

Check your understandingall correct = mastery ★
1
The sign pattern of the second quadrant is —
Check
2
The coordinates of the origin are (0, 0).
Check
3
The horizontal line X′X is called the ______.
Check
4
The point (−2, −5) lies in —
Check
5
The quadrants are counted clockwise from OX.
Check
6
Write the signs of the four quadrants in order and say which way they are counted.
Check2 marks
Next lesson →
3

Abscissa, ordinate, and points on the axes

भुज, कोटि और अक्ष पर बिंदु · Textbook 3.2 · abscissa · ordinate

New
Abscissa, ordinate, and points on the axesxy
Read the numbers on the axes, then join the points — the line is the picture of the equation.
The distance is written with a signNotes

The perpendicular distance of a point from the y-axis, measured along the x-axis, is its x-coordinate. It is also called the abscissa. The perpendicular distance from the x-axis, measured along the y-axis, is the y-coordinate, or the ordinate. The positive direction gives a positive sign and the negative direction a negative sign. Write the abscissa first, then the ordinate, in brackets.

Every point on the x-axis has ordinate 0, so the form is (x, 0). Every point on the y-axis has abscissa 0, so the form is (0, y). The origin is (0, 0). These points do not lie in a quadrant.

Worked exampleExample

Question: Point A is on the x-axis, 4 units from the origin in the positive direction. B is on the y-axis, 3 units from the origin in the positive direction. Write the coordinates.

Answer: The distance of A from the y-axis is 4 units and from the x-axis is 0, so A is (4, 0). The distance of B from the x-axis is 3 units and from the y-axis is 0, so B is (0, 3). The unit is the one chosen on the axes.

10-second revision
  • Abscissa = x-coordinate, ordinate = y-coordinate
  • x-axis: (x, 0) · y-axis: (0, y)
  • A point on an axis is not in a quadrant
Board tip · BSEBBoard tip

Do not swap the names abscissa and ordinate. The abscissa comes first. The ordinate is second.

Board tip · CBSEBoard tip

Do not put (−1, 0) in the third quadrant. It lies on the negative x-axis.

Check your understandingall correct = mastery ★
1
A point on the x-axis has the form —
Check
2
The point (0, 4) lies on the y-axis.
Check
3
The coordinates of the origin are ______.
Check
4
Of the points (−1, 0), (0, 5) and (2, −3), which lie on an axis and which lie in a quadrant? Name them.
Check3 marks
Next lesson →
4

Plotting a point when the coordinates are given

निर्देशांक देकर बिंदु आलेखित करना · Textbook 3.3 · ordered pair · Exercise 3.3

New
Plotting a point when the coordinates are gi…xyIIIIIIIV
The horizontal axis is x, the vertical is y. The signs change in the four quadrants.
The point is placed by walking from the originNotes

Plotting means placing a point at the given coordinates. For (3, 5), walk 3 units from the origin along the positive x-axis, then 5 units from there in the positive y direction. The point lies in the first quadrant. For (5, −4), take 5 on x and then 4 in the negative y direction. That is the fourth quadrant.

State the scale on both axes, for example 1 cm = 1 unit. (x, y) is an ordered pair. If x ≠ y, then (x, y) and (y, x) are different places. If x = y, they are the same point.

Worked exampleExample

Question: Where are the Exercise 3.3 points (−2, 4), (3, −1), (−1, 0), (1, 2) and (−3, −5)?

Answer: (−2, 4) is in the second quadrant. (3, −1) is in the fourth. (−1, 0) is on the negative x-axis, not in a quadrant. (1, 2) is in the first. (−3, −5) is in the third. Check by plotting them on the same scale.

10-second revision
  • Walk x first, then y
  • Ordered pair: a new order is a new place
  • (−1, 0) is on an axis, not in a quadrant
Board tip · BSEBBoard tip

Exercise 3.3 uses (−1, 0) as a trap. Write the axis, not a quadrant.

Board tip · CBSEBoard tip

On a plot keep the same scale on both axes unless the question asks for another scale. Write the unit.

Check your understandingall correct = mastery ★
1
The correct order for plotting (3, 5) is —
Check
2
If x ≠ y, then (x, y) and (y, x) are the same point.
Check
3
(x, y) is called an ordered ______.
Check
4
Which statement about (5, 2) and (2, 5) is correct?
Check
5
Write the steps to plot (−2, 4). Also name the quadrant. Scale: 1 cm = 1 unit.
Check3 marks
Next lesson →
5

The dice game — Activity 2

पासे वाला खेल — क्रियाकलाप 2 · Textbook 3.3 · Activity 2

New
The dice gamexyIIIIIIIV
The horizontal axis is x, the vertical is y. The signs change in the four quadrants.
Activity 2 — the race to (10, 10)Activity

Two players, two counters or coins, graph paper, and two dice of different colours — red and green. Both counters start at (0, 0). The red die increases x and the green die increases y.

A red 3 and a green 1 move the counter to (3, 1). Next, a red 1 and a green 4 move it to (3 + 1, 1 + 4) = (4, 5). The player who reaches (10, 10) first, without going past it, wins. If the abscissa or the ordinate would exceed 10, the turn is missed. Counters may not share a point. If you land on the other player, that counter returns to (0, 0).

The addition keeps the same orderNotes

Each move adds a new pair to the old pair. The red die is added to x and the green die to y. The axes are still called x and y. On a time-distance graph the names of the axes may change, but the rule of an ordered pair does not.

Worked exampleExample

Question: The counter is at (6, 8). The red die shows 3 and the green die shows 4. Is the move allowed?

Answer: The new place would be (6 + 3, 8 + 4) = (9, 12). The ordinate 12 is greater than 10, so the counter would pass the target. The turn is missed and the counter stays at (6, 8).

10-second revision
  • Start (0, 0), target (10, 10)
  • Red die is x, green die is y
  • A move past 10 is lost; a clash sends the other counter to the origin
Board tip · BSEBBoard tip

Activity 2 comes after Activity 1. In an answer write both the colour of the die and the axis.

Board tip · CBSEBoard tip

Reaching the target and passing the target are different. Passing it is not a win.

Check your understandingall correct = mastery ★
1
From (0, 0), a red 3 and a green 1 move the counter to —
Check
2
A move is still allowed if the abscissa becomes 11, because the counter got close to the target.
Check
3
If your counter lands on the other player, that counter returns to ______.
Check
4
The counter is at (2, 4). The next throw is red 5 and green 1. Find the new place and say whether the move is allowed.
Check2 marks
Next lesson →
6

The distance between two plotted points

दो अंकित बिंदुओं के बीच की दूरी · The measure after plotting · Pythagoras

New
The distance between two plotted pointsxyIIIIIIIV
The horizontal axis is x, the vertical is y. The signs change in the four quadrants.
Once the coordinates are known, the straight distance followsNotes

The exercises of this chapter ask you to name a point and to plot it. The straight distance between two such points is a further measurement. Join (x₁, y₁) and (x₂, y₂). The horizontal gap is x₂ − x₁ and the vertical gap is y₂ − y₁. These are the sides of a right triangle.

Distance = √[(x₂ − x₁)² + (y₂ − y₁)²]. The square removes a negative sign. The square root gives a length, so the distance is not negative. Keep the unit that was chosen on the axes.

Worked exampleExample

Question: Find the distance between A(1, 2) and B(4, 6). On the axes, 1 unit = 1 cm.

Formula: d = √[(x₂ − x₁)² + (y₂ − y₁)²]

Substitution: d = √[(4 − 1)² + (6 − 2)²] = √(3² + 4²) = √(9 + 16) = √25 = 5

Unit: 5 cm.

10-second revision
  • Distance = √[(x₂ − x₁)² + (y₂ − y₁)²]
  • The square root comes after the squares
  • Distance is not negative; the unit is the axis unit
Board tip · BSEBBoard tip

Do not write the distance as the sum of the gaps. For gaps 3 and 4, 3 + 4 = 7 is wrong. √(9 + 16) = 5 is right.

Board tip · CBSEBoard tip

Write the unit in the answer. The formula, the substitution and the unit should all appear in one answer.

Check your understandingall correct = mastery ★
1
The distance between (0, 0) and (3, 4) is —
Check
2
In the distance formula it is enough to write the sum of the squares and leave out the square root.
Check
3
The distance between A(1, 2) and B(4, 6) is 5 ______ when 1 unit = 1 cm.
Check
4
The correct distance formula is —
Check
5
Find the distance between P(−1, 2) and Q(2, 6). Write the formula, the substitution and the unit. 1 unit = 1 cm.
Check3 marks
6
The distance between two different points can be less than zero.
Check
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❓ Full question bank — with answers and explanations — 65 questions

No question is marked as a verified past paper. The BSEB set is a model for practice. CBSE items are CBSE-style, not a copy of any year’s paper.

Multiple choice

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Pick one option. A wrong try brings a hint.
1
Independent facts needed to fix a point in a plane are —
Board-style (practice)1 mark
2
The horizontal axis is called —
Board-style (practice)1 mark
3
The signs in the fourth quadrant are —
Board-style (practice)1 mark
4
The origin is —
Board-style (practice)1 mark
5
A point on the y-axis has the form —
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6
The point (−6, −2) lies in —
Board-style (practice)1 mark
7
The point (3, −4) lies in —
Board-style (practice)1 mark
8
(4, 3) and (3, 4) are —
Board-style (practice)1 mark
9
The abscissa is —
Board-style (practice)1 mark
10
The distance between (0, 0) and (6, 8) is —
Board-style (practice)1 mark
11
In Activity 1 the first number written is —
Board-style (practice)1 mark
12
Red 2 and green 4, from (0, 0), move the counter to —
Board-style (practice)1 mark
13
The point (−5, 0) lies —
Board-style (practice)1 mark
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True or false

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1
In the Cartesian plane the x-axis is vertical.
Board-style (practice)1 mark
2
In the first quadrant both coordinates are positive.
Board-style (practice)1 mark
3
The point (0, −4) lies on the x-axis.
Board-style (practice)1 mark
4
If x = y, then (x, y) and (y, x) are the same point.
Board-style (practice)1 mark
5
In Activity 2 the green die increases the x-coordinate.
Board-style (practice)1 mark
6
The distance formula adds the squares of both gaps and then takes the square root.
Board-style (practice)1 mark
7
Every point on an axis lies in some quadrant.
Board-style (practice)1 mark
8
In Exercise 3.1, (4, 3) and (3, 4) are the same crossing.
Board-style (practice)1 mark
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Fill in the blanks

0/8
1
The point where the axes cross is called the ______.
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2
The y-coordinate is also called the ______.
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3
The quadrants are counted in the ______ direction.
Board-style (practice)1 mark
4
The ordinate of a point on the x-axis is ______.
Board-style (practice)1 mark
5
In the distance formula the ______ of both gaps are added.
Board-style (practice)1 mark
6
The target point of Activity 2 is ______.
Board-style (practice)1 mark
7
A point with positive x and negative y is in the ______ quadrant.
Board-style (practice)1 mark
8
At 1 cm = 1 unit, the distance from (0, 0) to (8, 6) is ______ cm.
Board-style (practice)1 mark
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Match

0/2
1
Match the word with its meaning.
Board-style (practice)2 marks
Column B: A. The y-coordinate · B. (0, 0) · C. One fourth of the plane · D. The x-coordinate
1. Abscissa
2. Ordinate
3. Origin
4. Quadrant
2
Match the point with its place.
NCERT-style · practice2 marks
Column B: A. First · B. Second · C. Third · D. Fourth
1. (2, 3)
2. (−2, 3)
3. (−2, −3)
4. (2, −3)
↑ Question hub

Assertion–reason

0/5
Check both statements, then see whether the reason explains the assertion.
1

Assertion (A): (5, 1) and (1, 5) are different points.

Reason (R): (x, y) is an ordered pair and here the two numbers are not equal.

Board-style (practice)1 mark
2

Assertion (A): The coordinates of the origin are (0, 0).

Reason (R): The signs of the first quadrant are (+, +).

Board-style (practice)1 mark
3

Assertion (A): A point on the x-axis has the form (x, 0).

Reason (R): On the x-axis the abscissa is always zero.

Board-style (practice)1 mark
4

Assertion (A): (−4, 0) lies in the second quadrant.

Reason (R): When the ordinate is zero, the point lies on the x-axis.

Board-style (practice)1 mark
5

Assertion (A): The distance between (0, 0) and (5, 12) is 13 units.

Reason (R): √(5² + 12²) = √(25 + 144) = √169 = 13.

NCERT-style · practice1 mark
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Coefficient practice

0/4
These are not results of the maths chapter. They are only coefficient practice for H2 + O2 → H2O.
1
This is coefficient practice, not a result of this maths chapter. Fill coefficients for H2 + O2 making H2O (blank = 1). Complete the count for the water molecule.
Board-style (practice)1 mark
H2 + O2 → H2O
2
This is coefficient practice, not a result of this maths chapter. Fill coefficients for H2 + O2 making H2O (blank = 1). Keep the hydrogen atoms equal on both sides.
Board-style (practice)1 mark
H2 + O2 → H2O
3
This is coefficient practice, not a result of this maths chapter. Fill coefficients for H2 + O2 making H2O (blank = 1). Keep the oxygen atoms equal on both sides.
Board-style (practice)1 mark
H2 + O2 → H2O
4
This is coefficient practice, not a result of this maths chapter. Fill coefficients for H2 + O2 making H2O (blank = 1). A blank means the coefficient 1.
Board-style (practice)1 mark
H2 + O2 → H2O
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Classify

0/2
1
Place each point in its region.
Board-style (practice)2 marks
(1, 2)
(−1, 2)
(0, 2)
(3, 0)
2
Place each statement in the right class.
NCERT-style · practice2 marks
Column first, then row
The red die increases x
The teacher is an observer
The target is (10, 10)
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Very short answer

0/5
1
What is the Cartesian plane?
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2
Define abscissa and ordinate in one line each.
Board-style (practice)1 mark
3
Name the quadrants of (−3, 5) and (2, −4).
NCERT-style · practice2 marks
4
Why are the coordinates of the origin (0, 0)?
Board-style (practice)2 marks
5
Write the distance between (0, 0) and (3, 4), with the unit.
Board-style (practice)2 marks
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Short answer

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1
Write the signs of the four quadrants. What about a point on an axis?
Board-style (practice)3 marks
2
Find the distance between A(−2, 1) and B(2, 4). Write the formula, the substitution and the unit. 1 unit = 1 cm.
NCERT-style · practice3 marks
3
Write three rules of Activity 2: the colour of the dice, the limit 10, and a clash.
Board-style (practice)3 marks
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Long answer

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1
Describe the Cartesian plane and say where (2, 3), (−2, 3), (−2, −3) and (2, −3) lie. Then find the distance between (2, 3) and (2, −3). 1 unit = 1 cm.
Board-style (practice)5 marks
2
State the places of the five Exercise 3.3 points (−2, 4), (3, −1), (−1, 0), (1, 2) and (−3, −5). Separately say why (x, y) is called an ordered pair.
NCERT-style · practice5 marks
3
Find the distance from P(1, 1) to Q(4, 5). Then, as in Activity 2, show why adding (3, 4) to (1, 1) gives Q. 1 unit = 1 cm.
Board-style (practice)5 marks
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BSEB model paper · practice

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This model set is for practice. It is not a question from any year’s annual examination. Annual questions will be added only when a source page is available.

1
A point in the second quadrant can be —
BSEB model · practice (not an annual paper)1 mark
2
The point (7, 0) lies —
BSEB model · practice (not an annual paper)1 mark
3
Another name for the ordinate is the ______.
BSEB model · practice (not an annual paper)1 mark
4
The signs of quadrant III are (−, −).
BSEB model · practice (not an annual paper)1 mark
5
Find the distance between (0, 0) and (8, 15). Write the formula and the unit.
BSEB model · practice (not an annual paper)3 marks
6
This is coefficient practice, not a result of coordinate geometry. Balance H2 + O2 making H2O by filling coefficients (blank = 1).
BSEB model · practice (not an annual paper)1 mark
H2 + O2 → H2O
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CBSE-style questions

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These are competency-based practice questions. They are not copies of a CBSE paper.

1
A student places (−3, 4) in the fourth quadrant. The mistake is —
CBSE-style · competency-based (not a PYQ)1 mark
2
(5, 0) and (0, 5) are shown as one point on a graph. The conclusion is —
CBSE-style · competency-based (not a PYQ)1 mark
3

Assertion (A): In Activity 2 a move of red 2 and green 1 from (9, 8) should be missed.

Reason (R): Passing the target is the winning rule.

CBSE-style · competency-based (not a PYQ)1 mark
4
Writing the distance as √[(x₂ − x₁) + (y₂ − y₁)] is the correct formula.
CBSE-style · competency-based (not a PYQ)1 mark
5
On a map the school is (1, 2) and the house is (4, 6). The scale is 1 cm = 1 km. Find the distance and say why (2, 1) is not the school.
CBSE-style · competency-based (not a PYQ)3 marks
6
The counter is at (7, 9). A partner throws red 4 and green 2. What happens? Also give one example of an allowed move.
CBSE-style · competency-based (not a PYQ)3 marks
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🧠 What you learned + equation sheet

What you learned

WhatKeep this
Origin(0, 0)
First quadrant(+, +)
Second quadrant(−, +)
Third quadrant(−, −)
Fourth quadrant(+, −)
Distance√[(x₂−x₁)²+(y₂−y₁)²]

The notes are original writing. The textbook was used only for activity order and numbers. “Verified” will be used only on a question that has a source page.