Lesson Plan: Exterior Angles of a Polygon Mathematics • 8th Grade
This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to identify exterior angles of polygons, find their sum, and use them to solve problems.
Objectives
Students will be able to
- 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 given its number of sides 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,
- understand the relationship between exterior and interior angles and their sums in a convex polygon,
- find the number of sides a regular convex polygon has given the measure of one of its exterior angles,
- solve more complex problems, such as constructing and solving an algebraic equation to find a missing exterior angle measure in a given irregular convex polygon or identifying an exterior angle measure for a convex polygon taken from a real-world context.
Prerequisites
Students should already be familiar with
- regular and irregular polygons,
- identifying and classifying polygons as convex or concave,
- classifying polygons by their number of sides,
- interior angles of a polygon,
- constructing and solving simple algebraic equations.
Exclusions
Students will not cover
- radians.
