Question

Lot 21 is a trapezoid with the two bases

perpendicular to the road. The scale drawing
below uses the scale 1/2 inch = 40 feet.

Base 1=3.5 inches
Base 2=5 inches
height=4 inches

What is the approximate area of Lot 21?
(1 acre = 43,560 square feet)
A 1/2 acre
B 2 acres
C 2 1/2 acre
D 3 acres

Answer 1

Area of trapezoid is given by Area=1/2(a+b)*h
but the scale is:
1/2in=40 ft
hence
1 in=80 ft
the dimensions of the trapezium is:
Base=80*3.5=280 ft
Base=80*5=400 ft
Height=80*4=320 ft
thus the area is:
A=1/2(280+400)*320
A=108,800
but
1 acre=43560 ft²
Thus:
108800 ft²=108800/435602.4977=~2.5 acres

Answer: C] 2.5 acres