The perimeter of a rectangle is 60 cm. Take x as the breadth and express length in terms of x. If the area of a rectangle is 216 centimetre square, find the value of x.

Asked by khushdab | 1st Apr, 2020, 11:24: AM

Expert Answer:

Let the breadth of the rectangle be x.
We konw that,
Perimeter of a rectangle = 2(length + breadth)
2(length + x) = 60
→length = 30 - x
 
Area of a rectangle = length × breadth = 216  ....  given
→(30 - x)x=216
→ x2 - 30x + 216 = 0   
→ x2 - 18x - 12x + 216 = 0 
 → x(x - 18)-12(x - 18) = 0
→ (x - 18)(x - 12) = 0
→ x = 18 or x = 12
If breadth is 18cm then length is 12cm and if breadth is 12cm then length is 18cm.

Answered by Yasmeen Khan | 1st Apr, 2020, 01:33: PM