Question

the length of a rectangular field is 30m more than its breadth. if the perimeter is 640m. find the length of the field

Answer 1

the length is 175m. 2(x+x-30)=640
or,2(2x-30)=640
or,2x-30=320
or,2x=350
or,x=175

Answer 2

Let the breadth of the rectangular field be x

Then, length of the field = x + 30

According to question,

Perimeter = 640

And we know that perimeter of rectangle is 2( length + breadth)

Using this formula,

2( l + b ) = 640
2( x + 30 + x ) = 640
2x + 30 = 640/2
2x = 320- 30
x = 290/2 = 145


Therefore, Length of field = x + 30 = 145 + 30 = 175.