1 answer:
You might be interested in
Part A
The pen has a rectangular shape of length l and width, say w.
The perimeter (the fencing) of this rectangle is 2l+2w, as in the rectangle we have 2 opposing sides of length l and 2 opposing sides of length w.
This means that 2l+2w=400
subtract 2l from both sides:
2w=400-2l
divide by 2:
w=200-l, so we find that the width is 200-l.
part B
we are asked to find w when l=80 ft,
since we have w=200-l, we can find w for l=80 ft by substituting :
w=200-l=200-80=120 (feet)
Part C
The area of the pen when l=90 feet is:
(square feet)
The pen has a rectangular shape of length l and width, say w.
The perimeter (the fencing) of this rectangle is 2l+2w, as in the rectangle we have 2 opposing sides of length l and 2 opposing sides of length w.
This means that 2l+2w=400
subtract 2l from both sides:
2w=400-2l
divide by 2:
w=200-l, so we find that the width is 200-l.
part B
we are asked to find w when l=80 ft,
since we have w=200-l, we can find w for l=80 ft by substituting :
w=200-l=200-80=120 (feet)
Part C
The area of the pen when l=90 feet is: