first you know that you have 2 and 5 as similar numbers you both square them so that they become a ratio of area which is 4/25 after you do 4/25=20/x and you do cross multiply then you find 125. hope that helped understand.
o find the area of a regular polygon, all you have to do is follow this simple formula: area = 1/2 x perimeter x apothem. Here is what it means: Perimeter = the sum of the lengths of all the sides. Apothem = a segment that joins the polygon's center to the midpoint of any side that is perpendicular to that side.
