How many sides does a pentagon have if the sum of the interior angles is 900?

*The word pentagon is a name given to a polygon that has 5 sides. So in this case, the question should have used the word polygon instead of pentagon.

Sum of interior angles = (n - 2) x 180 where n is the number of sides.

The sum of the interior angles = 900

(n - 2) x 180 = 900

n - 2 =  900 ÷ 180

n - 2 = 5

n = 5 + 2 

n = 7

This is a 7-sided polygon.

Your pictures are upside down