Hi, I’m Ari. We can start coordinate geometry from the beginning, work through an example together, or practise a question. Tell me which step is confusing.
GCSE Maths · Geometry & measures
Coordinate geometry GCSE Questions and Worked Answers
Coordinates locate points using horizontal x then vertical y. Compare the coordinates to find horizontal and vertical changes; these give midpoint, distance and gradient. Use the scale on each axis, not a visual estimate.
Free AI tutor · GCSE coordinate geometry
Practise GCSE coordinate geometry for free with an AI tutor
Ask Ari for an explanation or work through an original exam-style question together.
Ari is an AI tutor and can make mistakes. Use the worked answers below to check important results.
Start with the meaning
What you need to know about coordinate geometry
On a grid, two numbers give a point's address. Start where the axes cross, called the origin (0, 0). For the point (3, 2), go 3 units right and 2 units up. The first number, x, records horizontal position; the second, y, records vertical position. Negative x means left, and negative y means down.
See the idea first
One journey supplies three useful measurements
From A = (1, 1) to B = (7, 5), the horizontal change is 7 − 1 = 6 and the vertical change is 5 − 1 = 4. Halfway along the straight journey means half of each change, reaching (4, 3). We call this point the midpoint. The same two changes are the legs of a right triangle whose sloping side is AB.
From problem to method
Typical problems you need to be able to solve
These are the main kinds of question in this topic. Each card first states the problem, then explains how to solve it.
Find a midpoint
What the problem asks: Find the midpoint of (2, 3) and (8, 7).
How to solve it: Average the two horizontal positions: (2 + 8)/2 = 5. Average the vertical positions: (3 + 7)/2 = 5. The midpoint is (5, 5).
Find a straight-line distance
What the problem asks: Find the distance between (1, 2) and (4, 6).
How to solve it: The changes are 3 across and 4 up. Pythagoras gives length √(3² + 4²) = 5 units; adding 3 + 4 measures a bent route instead.
Find gradient or a line equation
What the problem asks: Find the gradient and equation of the line through (1, 2) and (4, 8).
How to solve it: Gradient means vertical change per one horizontal unit. Here it is (8 − 2)/(4 − 1) = 6/3 = 2. For the equation, write y = 2x + c. Substitute (1, 2): 2 = 2 + c, so c = 0 and y = 2x.
A reliable routine
Use coordinates to solve a geometry problem
Use coordinate differences when a problem asks about a segment's halfway point, length or slope. The method depends on the requested quantity: averages locate the midpoint, Pythagoras measures the diagonal, and rise divided by run gives gradient.
- Identify what is required and write both points in the same x, y order.
- Work out horizontal and vertical changes, subtracting in the same direction.
- Use averages for midpoint, Pythagoras for distance, or vertical change ÷ horizontal change for gradient.
- Check the result against the positions and include units if the axes have them.
Check: Vertical lines have zero horizontal change, so their gradient is undefined. Their equation is x = a constant, not y = mx + c.
Fully worked
Coordinate geometry GCSE worked examples
Each solution explains the clue, why the method fits and how to check the result.
Example 1
Midpoint across the axes
Question
Find the midpoint of A = (−3, 2) and B = (5, 8).
The midpoint is (1, 5). It lies halfway in both coordinate directions.
Example 2
A missing endpoint
Question
A = (2, −1). The midpoint of AB is M = (5, 3). Find B.
From A to M, move 3 across and 4 up: a displacement written (3, 4), not the coordinates of a new point. Repeat that same change from M to B.
Check: averaging (2, −1) and (8, 7) gives (5, 3).
Example 3
Distance
Question
Find the distance between (−2, 1) and (4, 9).
Length is positive.
Example 4
A negative gradient
Question
Find the gradient through (1, 7) and (5, −1).
Moving one unit right lowers the line by 2 units.
Example 5
Line through two points
Question
Find the equation of the line through (2, 5) and (6, 13).
Write y = 2x + c and substitute (2, 5):
Thus y = 2x + 1. Check (6, 13): 2 × 6 + 1 = 13.
Example 6
Perpendicular line
Question
Find the equation of the line perpendicular to y = 2x + 1 through (4, 3).
Non-vertical perpendicular gradients multiply to −1, so the new gradient is −1/2.
Hence .
10 original questions · total 23 marks
Coordinate geometry GCSE exam-style questions
Try each question before opening its fully worked answer. The difficulty rises through the set.
Before you startAllow about 28 minutes · Show your working. Give exact answers unless a question asks you to round, and include units where needed. · answers start collapsed
Locate a point
Describe how to reach (−4, −2) from the origin.
Show worked answer
Move 4 units left, then 2 units down. Both coordinates are negative.
Midpoint
Find the midpoint of (1, 4) and (7, 10).
Show worked answer
Negative coordinates
Find the midpoint of (−6, −3) and (2, 5).
Show worked answer
Recover an endpoint
A = (−1, 2) and midpoint M = (2, 6). Find B.
Show worked answer
The change A to M is (3, 4). Repeat it:
Length
Find the distance from (1, 1) to (4, 5).
Show worked answer
Changes are 3 and 4.
Exact length
Find the exact distance from (−1, 2) to (3, 4).
Show worked answer
Changes are 4 and 2.
Gradient
Find the gradient through (−2, 5) and (4, 2).
Show worked answer
Vertical line
State the equation and gradient of the line through (3, −2) and (3, 7).
Show worked answer
Every point has x = 3, so its equation is x = 3. The horizontal change is zero, so the gradient is undefined.
Equation
Find the equation of the line through (0, −3) and (2, 5).
Show worked answer
The y-intercept is −3, so y = 4x − 3.
Perpendicular gradient
Find the gradient perpendicular to a line with gradient −3/4.
Show worked answer
The gradients multiply to −1:
Check: .
Examiner-style feedback
Common coordinate geometry mistakes
Write horizontal x first, vertical y second.
If you subtract B − A for y, do B − A for x too.
The straight-line distance is the hypotenuse, not the sum of the horizontal and vertical legs.
30-second recap
Choose, carry out, check
Translate the wording before you reach for a rule.
- x across, y up.
- Midpoint averages coordinates.
- Distance uses Pythagoras.
- Gradient is vertical change ÷ horizontal change.
Quick answers
Coordinate geometry FAQ
Can a midpoint have fractional coordinates?
Yes. Halfway between integer grid points need not be another integer grid point.
Is a negative gradient a negative length?
No. Gradient describes direction of change. Distance measures length and cannot be negative.
Content standards
Curriculum and rights review
A8/G11 coordinates and geometry across tiers, with A9 perpendicular-gradient extension labelled Higher. Questions, suggested marks, solutions and diagrams are original practice material, not official past-paper questions.
Official specification references