This is a complete lesson on angles in a semi-circle that will teach students to prove and use the rule that the angle in a semi-circle is a right angle. The lesson is designed with the new GCSE specification in mind.

### Lesson Objectives

- To be able to prove that an angle in a semi-circle is a right angle.
- To use the fact that a angle in a semi-circle is 90 degrees to solve problems.

### Who is this Lesson For?

This pack is designed for GCSE higher tier students. It could also be used with high ability Key Stage 3 students.

### What is Included?

Included in this download are the following:

- Full lesson plan for the ‘Angles in a Semi-Circle’ lesson, including introduction, teaching content, individual activities, plenary and suggested support and extension activities
- Angles in a Semi-Circle Demonstration
- Angles in a Semi-Circle Example
- Angles in a Semi-Circle Example 2
- Mini-Plenary
- Student Worksheet on Angles in a Semi-Circle
- Vote With Your Feet
- Circle Theorems Fact Sheet
- Complete Solutions to all Questions

### Lesson Progression

This is the first lesson in the Circle Theorems unit of work (the unit is also **available as a pack** including homework activities and a unit assessment).

The other lessons in the unit are: