Topic explanation

Standard explanation

An angle subtended by a diameter at the circumference is a right angle.

Key points

• angle in a semicircle
• understand the idea
• apply it carefully
• keep the ideas separate
• Angle In A Semicircle: An angle subtended by a diameter at the circumference is a right angle.
• WHAT — ANGLE IN A SEMICIRCLE: An angle subtended by a diameter at the circumference is a right angle.
• HOW — Use the idea: Identify what is given, select this topic's rule or evidence, apply it one step at a time, and check
• CORE UNDERSTANDING: An angle subtended by a diameter at the circumference is a right angle.

Labelled diagram