11. Find the measure of any interior angle in a regular 15-gon
(15-sided figure)

12. Find the measure of any interior angle in a regular 23-gon
(23-sided figure)
Round to the nearest hundredth

13. Find the measure of any interior angle in a regular 30-gon
(30-sided figure)

16. In a certain triangle, the measure of angle C is three times the measure of angle A, and the measure of angle B is the difference of the measures of the other two angles. Draw the triangle on scratch paper if necessary to determine the value of ‘x’.
3x + x + (3x – x) = 180
3x + x + 3x – x =180
6x = 180
x = 30
Write an equation to model this situation:
Find the measure of angle A:
x = 30
3x - x = 2x
2x = 60
Find the measure of angle B:
Find the measure of angle C:
3x = 90
180 degrees
Find the sum of angle A + angle B + angle C
Classify this triangle by it’s angles
Right triangle