Circle Theorems Angles In A Semi Circle — Interactive Lesson (Ages 14–16)

By the end of this unit, students will be able to:

1. understand the angles in a semi-circle theorem and its relevance to circles;
2. apply the theorem to determine angle measures in semi-circles and related scenarios;
3. solve problems involving angles in a semi-circle and their applications.

Curriculum Alignment: Key Stage 4: Geometry and measures

• Identify and apply circle definitions and properties, including: centre, radius, chord, diameter, circumference, tangent, arc, sector and segment
• {apply and prove the standard circle theorems concerning angles, radii, tangents and chords, and use them to prove related results}

Designed for ages 14–16 (UK Year 10–11 / US 9th Grade–10th Grade). Aligned to the UK National Curriculum; adaptable to US state standards.