Answer:
i. 24 sides
ii. 3960°
Step-by-step explanation:
Let the exterior angle be x.
x + 11x = 180°
12x = 180°
x = 15°
Hence the size of an interior angle is 11 times 15, which is 165°.
The formula for finding the sum of angles in an interior angle is this:
(n-2)180, with n being the number of sides the polygon has.
Hence, you can form this equation.
(n-2 )180 = 165n
180n-360=165n
-360=-15n
24=n
So, with there being 24 sides, the sum of all interior angles is 24 times 165 which equals 3960°
