Question

prove that the sum of the interior angles of an octagon is twice the sum of the interior angles of a pentagon

Answer 1

sum lf interior angle of any regular polygon can be given by
$180(n - 2)$
where n is the no. of sides of polygon
for pentagon
n = 5
so sum of all interior angles is
180[5-2]
180(3)
540°
and for octagon
n = 8
so sum of interior angles is
180(8-2)
180(6)
1080° = 2(540)

Answer 2

please mark my answer as a brain list