Question

Find the sum of the measures of the interior angles of a 21-gon.

Answer 1

well you have to use the equation (n-2(180)) where n represents the number of sides

so- 21 - 2 = 19 then multiply 19 x 180 = 3420

so the sum of all the interior angles in a 21-gon is equal to 3420 degrees

Answer 2

we know that
Sum of the measures of the interior angles of a polygon of n sides is equal to


`(n-2)*180`

where
n is the number of sides

in this problem

`n=21 \\ (21-2)*180=3420`°

Hence

sum of the measures of the interior angles of a 21 sided polygon is

`3420`°