8.1Polygon Angle Sums
Quick Answer
Interior angle sum of an n-gon = (n−2)×180°. Each interior angle of a regular n-gon = (n−2)×180°/n. The sum of exterior angles of any convex polygon is always 360°.
Essential Question
Why does the interior angle sum of a polygon increase by 180° for each additional side, and why is the exterior angle sum always 360°?
Learning Goals
- 1State the Polygon Interior Angle Sum Theorem.
- 2Find the interior angle sum of any polygon.
- 3Find each interior angle of a regular polygon.
- 4State and apply the Exterior Angle Sum Theorem.
Key Vocabulary
Interior Angle Sum Theorem
Sum of interior angles of an n-gon = (n−2)×180°.
Exterior Angle Sum Theorem
The sum of the exterior angles of any convex polygon is 360°.
Regular polygon
A polygon with all sides congruent and all angles congruent.
Full lesson content coming soon
Worked examples, guided practice problems, a workbook, quiz, and downloadable PDF resources will be added to this lesson in Phase 2. The learning goals and vocabulary above reflect the complete lesson scope.