Question

What is the measure on an interior angle of this polygon?

Answer 1

Answer:

a. 160

b. 18

Step-by-step explanation:

a. When the exterior and interior angles are added together, they add up to 180°. So this means that the interior angle equals 160°

$180-20=160$

b. The total of all exterior angles will always add up to 360°. With this information, you can divide 360 by the exterior angle to get the total sides of the shape.

$\frac{360}{20} =18$

Answer 2

Answer:

a) 160°

b) 18 sides

Step-by-step explanation:

Interior angle = 180 - exterior

= 180 - 20 = 160°

Each angle of a regular polygon:

[(n-2)×180]/n = 160

180n - 360 = 160n

20n = 360

n = 18

Alternate approach for no. of sides:

360/n = each exterior angle

360/n = 20

n = 360/20 = 18