GCSE Angles: All You Need to Know (with Examples and Questions)

Angles are a fundamental part of geometry, appearing in a wide range of topics and problem-solving scenarios in mathematics.

At GCSE level, students need to master basic angle facts such as angles around a point, angles in triangles and quadrilaterals, angles in parallel lines, and calculating interior and exterior angles in polygons. These skills are essential for tackling geometry problems with confidence.

Basic Angle Facts Summary

This video explains five fundamental angle rules, followed by a worked example of an exam question. The rules covered include:

• Angles in a triangle add up to 180°
• Angles on a straight line add up to 180°
• Angles in a quadrilateral add up to 360°
• Angles around a point add up to 360°
• Isosceles triangles have two equal angles

Angles in Parallel Lines

This video explores angles formed when two parallel lines are intersected by a transversal. It covers key angle types, including:

• Alternate angles
• Co-interior angles
• Corresponding angles

Angles in Polygons

This video explains how to calculate angles in polygons, covering both regular and irregular shapes. Topics include:

• The sum of interior angles
• How to find missing interior and exterior angles
• Determining the number of sides in a regular polygon

The rest of the guide on angles is not quite ready, but if you already know what you're doing, we have practice questions linked below.