CPM Homework Help : GC Problem 9-72

Which has greater measure: an exterior angle of an equilateral triangle or an interior angle of a regular heptagon ( $7$ -gon)? Show all work.

Hint:

Remember that the sum of all exterior angles is equal to $360°$ .

Step 1:

$\frac{360°}{3}=120°$ for each exterior angle, since it is an equilateral triangle.

Step 2:

$\text{Measure of one interior angle}=\frac{(n-2)(180)}{n}$

Step 3:

Substitute $7$ for $n$ and determine which of the two angles has a greater measure.