GCSE Higher · Free visual lesson

Angles in a Semicircle

Name: Angles in a Semicircle
Uploaded: 2026-10-18
Duration: PT131.867S
Description: Understand why an angle at the circumference subtended by a diameter is 90°. Watch the diagram and proof in this free visual GCSE Maths lesson.

Understand why an angle at the circumference subtended by a diameter is 90°. Watch the diagram and proof in this free visual GCSE Maths lesson.

Visual GCSE Maths lessonPause and replay any step

Check that the line is a diameter, follow the proof using equal radii, and see how to recognise the theorem in a question.

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