Edexcel IGCSE Maths topic guide

Geometry, Trigonometry and Vectors

Geometry marks depend on selecting a justified relationship and communicating it clearly. Diagrams are not always drawn to scale, so angle facts, formulae and units should drive the method.

Foundation and Higher relevance

Foundation and Higher include shape, measure, transformations and right-angled trigonometry. Higher extends to vectors, proof, 3D work and sine or cosine rules.

Topic coverage

Angle rules and polygons
Properties of 2D and 3D shapes
Constructions and loci
Transformations
Similarity and congruence
Pythagoras in 2D and 3D
Right-angled trigonometry
Sine and cosine rules
Area using ½ab sin C
Area, surface area and volume
Vectors
Compound measures

Worked example

Question: A right-angled triangle has perpendicular sides 7 cm and 9 cm. Find the hypotenuse.

Identify the hypotenuse as the side opposite the right angle.
Apply Pythagoras: c² = 7² + 9² = 49 + 81 = 130.
Take the positive square root because a length is required.

Answer: c = √130 cm, approximately 11.4 cm.

Common errors

Using the hypotenuse as one of the shorter sides in Pythagoras.
Using degrees and radians inconsistently on a calculator.
Omitting squared or cubed units for area and volume.

Revision checklist

I state the theorem or formula before substituting.
I keep full calculator precision until the final line.
I include correct units and a justified degree of accuracy.