Answer:
20- gon
Explanation:
the sum of the interior angles of a polygon is
sum = 180° (n - 2) ← n is the number of sides
given the sum of the interior angles is 3240° , then
180° (n - 2) = 3240 ( divide both sides by 180° )
n - 2 = 18 ( add 2 to both sides )
n = 20
then the polygon is a 20- gon