JCHL Geometry

JCHL Geometry

Angles, triangles, constructions and transformations — see the shapes and learn the rules, step by step.

Your progress through this topic0 of 12 lessons

Lessons in this topic

All 12 lessons, in order — each one ticks off as you open it.

Key ideas in this topic

Every formula from these lessons in one place. The green ones are printed in the log tables booklet you get in the exam — the red ones you learn off.

★ Must learn
Theorems on the course

14 theorems (numbers 1–6, 9–15, 19). Recognise them all; you only prove five — Theorems 4, 6, 9, 14 and 19.

JCHL Geometry 1

★ Must learn
Corollaries

5 corollaries (1–5) — results that follow directly from a theorem.

JCHL Geometry 1

★ Must learn
Axioms

5 axioms (1–5) — statements accepted without proof that everything is built on.

JCHL Geometry 1

★ Must learn
Proving triangles congruent

Use one of the four conditions: SSS, SAS, ASA or RHS.

JCHL Geometry 1

★ Must learn
Proving triangles similar

Equal angles, and corresponding sides in the same ratio.

JCHL Geometry 1

★ Must learn
Converse of a theorem

Swap the “given” and the “to prove” — a converse is not always true.

JCHL Geometry 1

★ Must learn
Constructions on the course

15 constructions (numbers 1–15).

JCHL Geometry 1

★ Must learn
Translation
Translation

A slide — every point moves the same distance in the same direction.

JCHL Geometry 7

★ Must learn
Axial symmetry
Axial symmetry

A flip in a line — the image is the mirror image in the axis.

JCHL Geometry 7

★ Must learn
Central symmetry
Central symmetry

A flip through a point — every point passes through the centre to the far side.

JCHL Geometry 7

★ Must learn
Rotation
Rotation

A turn about a point through an angle.

JCHL Geometry 7

★ Must learn
Enlargement
Enlargement

A scaling by a factor from a centre — every length is multiplied by the scale factor.

JCHL Geometry 7