Question

A circular piece of fabric has a radius of 1.2 ft. The fabric sells for $5.40 per ft². What is the total cost of the circular piece of fabric? Use 3.14 for pi.
A 6.48
B 20.35
C 24.42
D 40.69

Answer 1

The answer is $24.41

Step 1. Calculate the area of the circular piece of fabric.
Step 2. Multiply the area of the piece by the price of $5.40 per ft² to get the total cost.

Step 1.
The area (A) of the circle with radius r is:
A = π r²
π = 3.14
r = 1.2 ft

A = 3.14 * (1.2 ft)²
A = 3.14 * 1.44 ft²
A = 4.52 ft²

Step 2.
Make a proportion
1 ft² costs $5.40
4.52 ft² cost x

1 ft² : $5.40 = 4.52 ft² : x
x = 4.52 ft² * $5.40 / 1 ft²
x = $24.41