Answer:
pentagon
Explanation:
Recall that for any regular polygon, the number of sides and the interior angles are related through the following formula.
Interior Angle, θ = 180(n-2) / n ; where n is the number of sides
Rearranging :
θ = 180(n-2) / n
nθ = 180 (n-2)
nθ = 180n - 2(180)
nθ = 180n - 360
180n - nθ = 360
n(180 - θ) = 360
n = 360 / (180 - θ) (given that θ = 108°)
n = 360 / (180 - 108)
n = 5
since the polygon has 5 sides, it is a pentagon