The square and rectangle have the same perimeter of 40 cm. Find the area of each shape
The square and rectangle have the same perimeter of 40 cm. Find the area of each shape if the width of the rectangle is 7 cm?
1. Find the side of the square if its perimeter is 40 cm. To do this, divide the perimeter by 4, since the sides of the square are the same:
40: 4 = 10 cm;
2. Find the area of a square with a side of 10 cm:
10 * 10 = 100 cm2;
3. Find the sides of the rectangle if one side is 7 cm and the perimeter is 40 cm. Since the formula for the perimeter of the square is P = 2 * (a + b), then to find the unknown side, you need to divide the perimeter by 2 and subtract the known side:
40: 2 – 7 = 13 cm;
4. Find the area of a rectangle with sides 7 and 13 cm:
7 * 13 = 91 cm2.
Answer: the area of the square is 100 cm2, and the area of the rectangle is 91 cm2.