Question

A square of side 72 cm and a rectangle of length 90 cm have same perimeter. Find the difference in areas ?

A)216cm2
B)304cm2
C)324cm2
D)328cm2

Answer 1

C) 324cm²

Explanation:

1) they have the same perimeter so to find it you add all four sides of the square because they are all the same ( 72+72+72+72=288)

2) now you multiply 90 by 2 because the rectanglehas to sides of the same length(90×2=180) the answer you get you are going to subtract to 288 (288-180=108)

3) now divide 108 by 2 (108÷2= 54) the answer you get equals the width of the side of the rectangle

4) to get the area of the rectangle you multiply 54 with 90 (54×90=4,860) to get the area of the square you multiply 72 times 72 (72×72=5,184)

5) now you subtract 5,184 and 4,860 ( 5,184-4,860= 324cm²)

Answer 2

324 cm²

Explanation:

→ Work out perimeter of square

72 + 72 + 72 + 72 = 288

→ Work out the width of the rectangle

288 - (90 × 2) = 108

108 ÷ 2 = 54

→ Work out area of square

72 × 72 = 5184 cm²

→ Work out area of rectangle

90 × 54 = 4860 cm²

→ Minus the areas from each other

5184 cm² - 4860 cm² = 324 cm²