Perpendicular lines

Definition

Lines that meet at a right angle of $90^\circ$ .

Used by AQA, Edexcel and OCR

How each exam board covers it

AQA GCSE Mathematics · 8300

Specification A9, G1 · Paper 1, Paper 2, Paper 3

Lines that meet at a right angle. For two lines with defined gradients, their gradients multiply to $-1$ .
Perpendicular lines meet at a right angle.
Revise: Straight-Line Graphs
Lines that intersect at an angle of exactly .

Exam tips

1
Do not confuse the rules: parallel lines have equal gradients; perpendicular lines have gradients whose product is $-1$ .
2
Use $\parallel$ for parallel lines and $⊥$ for perpendicular lines; do not replace either symbol with an equals sign.

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9 0^{\circ}

Revise: Geometric Notation: Points, Lines and Planes

AQA Mathematics past papers

Edexcel GCSE Mathematics · 1MA1

Specification A9, G1, G11 · Paper 1, Paper 2, Paper 3

Lines that meet at a right angle.
Perpendicular lines meet at a right angle.
Revise: Straight-Line Graphs
Revise: Geometric Terms and Notations
Revise: Coordinate Geometry Problems

Edexcel Mathematics past papers

OCR GCSE Mathematics · J560

Specification 7.02b, 8.01a, 8.02c · Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Foundation), Paper 4 (Higher), Paper 5 (Higher), Paper 6 (Higher)

Lines that meet at a right angle. For two non-vertical, non-horizontal perpendicular lines, their gradients multiply to $-1$ .
On this OCR course, identifying and finding equations of parallel lines begins at Foundation tier; perpendicular lines and circle tangents are additional Higher-tier content.
Revise: Parallel and Perpendicular Lines
Revise: Shape Terminology
Two lines that meet at a right angle of $90^\circ$ .
Revise: Perpendicular Lines

OCR Mathematics past papers

⊥

3

For non-vertical parallel lines, keep the gradient exactly the same. For perpendicular lines with non-zero, defined gradients, take the reciprocal and change the sign; treat horizontal and vertical lines as a separate pair.