Area is a derived equation from the lengths of the side. To determine the ratio of the perimeters of the given figure, we have to get the square root of the given ratio of the areas. This gives us the new ratio of,
ratio of perimeter = 4:5
If we are to let x be the perimeter of the second polygon, we use the equation,
20/x = 4/5
The value of x from the equation is 25 cm.
