Lesson Plan: Interior and Exterior Angles of a Polygon
This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to identify interior angles and exterior angles of polygons, find their sum, and use them to solve problems.
Objectives
Students will be able to
- find the sum of the interior angles of a convex polygon given its number of sides using the formula,
- find the measure of the interior angle of a regular convex polygon given its number of sides using the formula,
- find the measure of an interior angle in an irregular convex polygon given its number of sides and the measure of the other interior angles in the polygon,
- understand the relationship between interior and exterior angles and their sums in a convex polygon,
- understand that the sum of the exterior angles of a convex polygon is 360 degrees,
- find the measure of the exterior angle of a regular convex polygon by dividing 360 by the number of sides,
- find the measure of an exterior angle in an irregular convex polygon given the measure of the other exterior angles in the polygon,
- find the number of sides a regular convex polygon has given the measure of one of its interior or exterior angles,
- solve more complex problems, such as constructing and solving an algebraic equation to find a missing angle measure in a given irregular convex polygon or identifying a missing angle measure for a convex polygon taken from a real-world context.
Prerequisites
Students should already be familiar with
- the sum of the angles in a triangle,
- regular and irregular polygons,
- identifying and classifying polygons as convex or concave,
- classifying polygons by their number of sides,
- constructing and solving simple algebraic equations.
Exclusions
Students will not cover
- radians.