Question

The perimeter of a parallelogram is 120cm. If one of the sides is greater than the other by 10cm,

find the length of all the sides of the parallelogram

Answer 1

Two of the sides are 25cm and the other two sides are 35cm.

Explanation:

The perimeter is the distance all the way around the shape.

The shape is a parallelogram, so two sides across from each other are the same length. And the other two sides are also the same as each other. See image.

The shorter sides can be labelled x and the longer sides can be labelled x + 10. This is because the question said the long side is 10cm more than the short side.

see image.

Add up all the sides to make them equal to the perimeter. Set it equal to 120. See image.

Solve for x.

x + x+10 + x + x+10 = 120

4x + 20 = 120

Subtract 20.

4x = 100

Divide by 4.

x = 25

The short sides are 25cm and the long sides are 35cm.

Check:

25+35+25+35=

120 Check!