The column is written first.
Column 5 and row 3. (3, 5) is another desk.
Class 9 · Maths · Chapter 3 · बिहार बोर्ड (BSEB)CBSE · NCERT 2026-27
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.
Last 7 days:
Everything is saved in this phone/browser — no login.
This chapter has no Short on the channel yet, so ten empty cards are not shown. The notes, diagrams and checks are complete.
दो सूचनाएँ और बैठक योजना — क्रियाकलाप 1 · Textbook 3.1 · Activity 1 · Exercise 3.1
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.
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.
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.
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.
The Cartesian name comes from Descartes. If the paper asks for the name of the system, write Cartesian, not only “graph”.
The column is written first.
Column 5 and row 3. (3, 5) is another desk.
False — a change of order changes the column and the row.
The teacher desk is not on the plan.
An observer. The desks belong to the students.
The left edge and the bottom line.
Two distances. Distance from one edge does not fix the place.
Give the perpendicular distance from the left edge of the table and the perpendicular distance from the front edge. One distance alone does not fix the lamp.
कार्तीय तल और चार चतुर्थांश · Textbook 3.2 · axes · signs
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.
| Quadrant | Signs | Enclosed 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 |
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.
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.
Do not write the count as clockwise. The book counts I, II, III, IV anticlockwise from OX.
Upper left.
(−, +). x is negative and y is positive.
True — the distance from both axes is zero.
The vertical line is the y-axis.
The x-axis. Y′Y is the y-axis.
Both coordinates are negative.
The third quadrant, signs (−, −).
False — the count is anticlockwise: I, II, III, IV.
First (+, +), second (−, +), third (−, −), fourth (+, −). The count is anticlockwise from the positive x-axis.
भुज, कोटि और अक्ष पर बिंदु · Textbook 3.2 · abscissa · ordinate
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.
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.
Do not swap the names abscissa and ordinate. The abscissa comes first. The ordinate is second.
Do not put (−1, 0) in the third quadrant. It lies on the negative x-axis.
The ordinate is zero.
(x, 0). On the y-axis it is (0, y).
True — the abscissa is 0, so the point is on the vertical axis.
Both distances are zero.
(0, 0).
(−1, 0) is on the negative x-axis. (0, 5) is on the positive y-axis. (2, −3) is in the fourth quadrant because the signs are (+, −). Points on an axis are not counted in a quadrant.
निर्देशांक देकर बिंदु आलेखित करना · Textbook 3.3 · ordered pair · Exercise 3.3
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.
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.
Exercise 3.3 uses (−1, 0) as a trap. Write the axis, not a quadrant.
On a plot keep the same scale on both axes unless the question asks for another scale. Write the unit.
The abscissa comes first.
From the origin, 3 units on positive x, then 5 units on positive y.
False — order matters. They are equal only when x = y.
The order must not be swapped when x ≠ y.
An ordered pair.
5 ≠ 2.
They are different points because the coordinates are not equal.
Take 1 cm = 1 unit on both axes. From the origin walk 2 units along the negative x-axis. From there walk 4 units in the positive y direction and mark the point. The signs are (−, +), so the point is in the second quadrant.
पासे वाला खेल — क्रियाकलाप 2 · Textbook 3.3 · Activity 2
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).
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.
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).
Activity 2 comes after Activity 1. In an answer write both the colour of the die and the axis.
Reaching the target and passing the target are different. Passing it is not a win.
10-second revision
Red is x.
(3, 1). Green is added to y.
False — if the abscissa or the ordinate would exceed 10, the turn is missed.
The starting place.
(0, 0).
The new place is (2 + 5, 4 + 1) = (7, 5). Both coordinates are less than 10, so the move is allowed. The counter moves to (7, 5).
दो अंकित बिंदुओं के बीच की दूरी · The measure after plotting · Pythagoras
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.
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.
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.
Write the unit in the answer. The formula, the substitution and the unit should all appear in one answer.
10-second revision
√(9 + 16).
√(3² + 4²) = √25 = 5 units.
False — the sum is in square units. A length needs the square root.
The unit of the axes.
5 cm.
Pythagoras, then the root.
Inside the square root, the squares of both gaps are added.
d = √[(x₂ − x₁)² + (y₂ − y₁)²] = √[(2 − (−1))² + (6 − 2)²] = √(3² + 4²) = √(9 + 16) = √25 = 5 cm.
False — a length under a square root is not negative. For different points the distance is positive.
Pick a type. The 30 lesson checks are separate — each lesson has as many as its topic needs. All correct earns mastery ★.
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.
On a line, one number is enough.
Two. One horizontal reference and one vertical.
Y′Y is vertical.
X′X is the x-axis.
Positive x, negative y.
(+, −).
Both distances are zero.
(0, 0).
The abscissa is zero.
(0, y).
Both negative.
The third quadrant.
Positive x, negative y.
The fourth quadrant.
4 ≠ 3.
The order differs, so the points differ.
The ordinate is y.
The abscissa is the x-coordinate.
√(36 + 64).
√(36 + 64) = √100 = 10 units.
In (5, 3) the 5 is the column.
The column. The row is the second number.
Red is x.
(2, 4).
The ordinate is 0.
On the negative x-axis. That is not a quadrant.
False — the x-axis is horizontal. The y-axis is vertical.
True — the signs are (+, +).
False — the abscissa is 0, so it lies on the negative y-axis.
True — when the two numbers are equal, a change of order does not move the point.
False — the green die increases y. The red die increases x.
True — that is the Pythagoras form.
False — the quadrants are the regions between the axes. The axes themselves are not counted in them.
False — a change of order is a crossing of different streets. Each name is exactly one crossing.
The origin.
The coordinates are (0, 0).
The ordinate.
The abscissa is x.
Anticlockwise.
Starting at OX.
0.
The form is (x, 0).
The squares.
Then the square root.
(10, 10).
The start is (0, 0).
The fourth.
The signs are (+, −).
10.
√(64 + 36) = √100.
The abscissa is x, the ordinate is y, the origin is (0, 0), and a quadrant is a fourth of the plane.
The signs in order are (+,+), (−,+), (−,−), (+,−).
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.
Both are true and R is the correct reason.
Assertion (A): The coordinates of the origin are (0, 0).
Reason (R): The signs of the first quadrant are (+, +).
Both are true, but R does not explain the origin.
Assertion (A): A point on the x-axis has the form (x, 0).
Reason (R): On the x-axis the abscissa is always zero.
A is true. R is false — on the x-axis the ordinate is zero, not the abscissa.
Assertion (A): (−4, 0) lies in the second quadrant.
Reason (R): When the ordinate is zero, the point lies on the x-axis.
A is false. R is true — this is why the point is not in a quadrant.
Assertion (A): The distance between (0, 0) and (5, 12) is 13 units.
Reason (R): √(5² + 12²) = √(25 + 144) = √169 = 13.
Both are true and R explains A by the calculation.
(1, 2) is in the first, (−1, 2) in the second, and (0, 2) and (3, 0) are on the axes.
The seating plan is Activity 1. The dice and (10, 10) are Activity 2.
The plane formed by two perpendicular number lines X′X and Y′Y is the Cartesian plane. Their crossing is the origin.
The abscissa is the x-coordinate of the point. The ordinate is the y-coordinate of the point.
(−3, 5) is in the second quadrant. (2, −4) is in the fourth quadrant.
The origin lies on both axes, so both perpendicular distances are zero.
√(3² + 4²) = √25 = 5 units.
First (+, +), second (−, +), third (−, −), fourth (+, −). A point on an axis is not in a quadrant. On the x-axis it is (x, 0) and on the y-axis it is (0, y).
d = √[(2 − (−2))² + (4 − 1)²] = √(4² + 3²) = √(16 + 9) = √25 = 5 cm.
The red die adds to x and the green die to y. Neither coordinate may exceed 10, or the turn is missed. If you land on the other counter, it returns to (0, 0).
The x-axis is horizontal and the y-axis is vertical, crossing at (0, 0). The points lie in the first, second, third and fourth quadrants in that order. The distance is √[(2 − 2)² + (−3 − 3)²] = √(0 + 36) = 6 cm.
In order: second quadrant, fourth quadrant, negative x-axis, first quadrant, third quadrant. (x, y) is an ordered pair because if x ≠ y then (y, x) is a different place.
d = √[(4 − 1)² + (5 − 1)²] = √(9 + 16) = √25 = 5 cm. The sum is (1 + 3, 1 + 4) = (4, 5), which is Q. A red 3 and a green 4 would be a move of that kind.
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.
The signs are (−, +).
(−4, 5).
The ordinate is zero.
On the positive x-axis.
The y-coordinate.
The abscissa is x.
True.
d = √(8² + 15²) = √(64 + 225) = √289 = 17 units.
These are competency-based practice questions. They are not copies of a CBSE paper.
The real signs are (−, +).
(−3, 4) is in the second quadrant. The student swapped the signs.
One is on one axis, the other on the other axis.
(5, 0) is on the x-axis and (0, 5) is on the y-axis. They are not one point.
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.
A is true because x would become 11. R is false — passing the target cancels the move.
False — the squares of the gaps are added, then the square root.
d = √[(4 − 1)² + (6 − 2)²] = √(9 + 16) = 5 km. (2, 1) is a different place because the order changed, so it is not the school.
(7 + 4, 9 + 2) = (11, 11). Both coordinates exceed 10, so the turn is missed and the counter stays at (7, 9). Red 1 and green 1 is allowed: (8, 10).
Switch board with BSEB | CBSE above. The lessons follow the same NCERT chapter.
This page has no verified annual-exam question, because no source page has been added. The model set below is practice in the board pattern.
🏛️ Model questions on one page →
The verified label will be used only when a source page for the question is available.
These are case and assertion-reason practice items. Do not treat them as past CBSE questions.
Wrong questions return soon; correct ones return after a few days.
What you learned
| What | Keep 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.