Side AB of rectangle ABCD is three times the size of side BC Find the sides of the rectangle if its perimeter is 72 cm.

1) Let us find out what is the length of the BC side, if it is known that it is equal to the DA side and 3 times less than the AB side, which is equal to the DC side, and the perimeter of the quadrangle is 72 cm.We compose an equation where:

X – sides of the aircraft;

3X – AB side.

72 – perimeter.

(X + 3X) * 2 = 72;

2X + 6X = 7;

8X = 72;

X = 72/8;

X = 9 cm.

2) Let us find out what is the length of the side AB of the quadrangle ABCD, if it is known that it is 3 times longer than the side BC, and the length of the side BC was 9 cm.

9 * 3 = 27 cm.

Answer: side AB is 27 cm long, and BC is 9 cm long.