Question

The length of a rectangle is twice its width. If the area of the rectangle is 72in², find its perimeter

Answer 1

Let breadth be x

• Length=2x

`\\ \sf\longmapsto Area=Length* Breadth`

`\\ \sf\longmapsto 72=2x(x)`

`\\ \sf\longmapsto 2x^2=72`

`\\ \sf\longmapsto x^2=(72)/(2)`

`\\ \sf\longmapsto x^2=36`

`\\ \sf\longmapsto x=√(36)`

`\\ \sf\longmapsto x=6`

• Length=6×2=12in
• Breadth=6in

`\\ \sf\longmapsto Perimeter=2(L+B)`

`\\ \sf\longmapsto Perimeter=2(12+6)`

`\\ \sf\longmapsto Perimeter=2(18)`

`\\ \sf\longmapsto Perimeter=36in`