Question

A 3-ft.-wide sidewalk surrounds a rectangular plot that measures 20 ft. by 30 ft. Find the area of the sidewalk.
936 ft.²
600 ft.²
336 ft.²

Answer 1

You are given the dimensions of the rectangular plot so you know the area of that.
\[20*30 = 600ft^{2}\]
You can find the area of the plot AND the sidewalk combined (26 by 36 feet since the sidewalk is 3 feet on EACH side)
\[26*36=936ft^{2}\]
Now just subtract the area of both the plot and the sidewalk from the area of just the plot to get your answer.