# Lesson Plan: Angles of Tangency Mathematics • 11th Grade

This lesson plan includes the objectives and prerequisites of the lesson teaching students how to identify the angle of tangency in a circle and find its measure using the measure of its subtended arc, inscribed angle, or central angle subtended by the same arc.

#### Objectives

Students will be able to

• find the measure of an angle of tangency in a circle using the measure of arcs and vice versa, including solving linear equations,
• find the measure of an angle of tangency in a circle using the measure of an inscribed angle subtended by the same arc and vice versa including solving linear equations,
• find the measure of an angle of tangency in a circle using the measure of a central angle subtended by the same arc and vice versa, including solving linear equations,
• proving that a ray or a straight line is tangent to a circle passing through some given points using the concept of the angle of tangency.

#### Prerequisites

Students should already be familiar with

• triangles and their properties,
• measures of arcs, central, and inscribed angles,
• theories of parallel chords and tangents in a circle,