The perimeter of a rectangular field is 374 yard. If the length of the field is 99 yards, what is its width?

What is important in this problem is the equation for Perimeter

Perimeter = 2Length + 2Width

So 99 = length (l)

374 = 2 (99) + 2 (w)

374 = 198 + 2w

Subtract

176 = 2w

Divide both sides by 2

88 = w

The Width is 88 yards

The perimeter of a rectangle is 2*L+2*W. Knowing that length is 99, we do 2*99 to get 198. Do 374-198, which is 176, we know that that is twice the length of the width. Therefore the width is 176/2, which is 88.