Lesson 5.2
- Author:
- diana :))
Investigation
Is there an exterior angle sum ?
Steps 1-5
Draw a large polygon and extend its sides to form a set of exterior angles.
Measure all except one
Use polygon sum to get the remaining angle measure
use the linear pair conjecture to find it
calculate the sum of the measure of the exterior angles
repeat step 1-4 with other polygons
Exterior Angle Sum Conjecture
For any polygon, the sum of the measures of a set of exterior angles is 360°
Steps 6-8
study the figure above
using the polygon sum conjecture, write a formula for the measure of each interior angle in an equiangular polygon
using the exterior angle sum conjecture, write the formula for the measure of each exterior angle in an equiangular polygon
Equiangular polygon Conjecture
You can find the measure of each interior angle of an equiangular n-gon by using either of these formulas: 180 - (360/n) or (180(n - 2)/n.