Answer:
64√3 ft²
Step-by-step explanation:
The short leg of the triangle has length (8 ft)(cos 60°), or (8 ft)(1/2), or 4 ft.
The long leg (represented by the dashed line) is (8 ft)(sin 60°), or
(8 ft)(√3/2), or 4√3. This is also the width of the horizontal trapezoid.
The area of this horizontal trapezoid is:
(sum of horizontal sides)
A = ------------------------------------- * (width)
2
Here, the area is:
(18 ft + (18 ft - 4 ft)
= ------------------------------------- * (4√3)
2
32 ft
= ----------- * 4√3 = 64√3 ft²
2
I think it would be 25.6 miles per hour
