Hello, Myah,
Let L be the length and W the width. We are told that L =W + 4. We also know the area is equal to W*L, which is 60 m2 (I assume the 60 meters is meant to be 60 square meters)
Use the first definition of L in the area equation:
A=W*L
A=W(W+4)
60 = W2 +4W
W2 +4W - 60 = 0
We can factor this into (W - 6)(W + 10)
That nmakes the roots W=6 and W=-10. -10 m2 makes no sense for our 3D world, but W = 6 does.
The dimensions are thus:
W = 6m2, and
L = 10m2
WL = 60m2
Bob