Answer:
0.314 gallon is required to cover a circular region with a radius of 40 feet
Step-by-step explanation:
Given
a gallon of paint will cover about 400 square feet in a single coat
To Find:
Number of gallons required to cover a circular region with a radius of 40 feet = ?
Solution:
Step 1: Finding Area of the circular region
The area of the circular region, A =

where r is the radius
Now substituting r = 40 , we get
A =


Step 2: Finding the number of gallons of paint required
To cover 400 sq feet = 1 gallon
so to cover 1 square feet =
gallon
Now to cover 125.6 ft we need


=> 0.314 gallon