10. The perimeter of a parallelogram is 72 meters. The width of the parallelogram is 4 meters less than its length. Find the length and the width of the parallelogram.

Let,

Length = a

Width = b

a-b=4 - - eq (1)

since perimeter of parallelogram P=2 (a+b)

therefore

2a+2b=72 - - eq (2)

eq (1) = >

a=b+4

substitute the value of a in eq 2

Eq (2) = >

2 (b+4) + 2b=72

2b+8+2b=72

4b=72-8

4b=64

b=16

Substitue the value of b in eq (1)

Eq (1) = >

a-16=4

a=20