Answer:
B) 697.5 ft²
Step-by-step explanation:
The quickest way to approach this question is to calculate the area of the entire rectangle, then subtract the area of the small rectangle (the rectangle missing at the top).
Formula
Area of a rectangle = width x length
⇒ Area of large rectangle = 20 ft x 45 ft
= 900 ft²
⇒ Area of small rectangle = 7.5 ft x (45 - 8 - 10) ft
= 7.5 ft x 27 ft
= 202.5 ft²
⇒ Area of the pool cover = large rectangle - small rectangle
= 900 ft² - 202.5 ft²
= 697.5 ft²
As one equation:
Area of pool cover = (20 x 45) - (7.5 x (45 - 8 - 10))
= 900 - (7.5 x 27)
= 900 - 202.5
= 697.5 ft²
