Lance is making a poster for Bike Safety Week. The diameter of circle A is 18 in.

Question

If the area of circle B is 1/5 the area of circle A, what is the area of circle B?

Answer 1

First, we need to find the area of circle A:

Area of circle A = πr^2
where r is the radius of circle A

Since the radius of circle A is half the diameter, the radius of circle A is 18/2 = 9 inches.

Area of circle A = π(9)^2
Area of circle A = π(81)
Area of circle A = 81π square inches

Now, we need to find 1/5 of the area of circle A for circle B:

Area of circle B = (1/5) * 81π
Area of circle B = 81π / 5
Area of circle B = 16.2π square inches

Therefore, the area of circle B is 16.2π square inches.

Answer 2

A.
203.472 in2
B.
50.868 in2
C.
254.34 in2
D.
25.434 in2

Answer 3

To find the correct area of circle B, we first need to calculate the area of circle A:

Area of circle A = πr^2
Since the diameter of circle A is 18 inches, the radius of circle A is half of that, which is 9 inches.

Area of circle A = π(9)^2
Area of circle A = π(81)
Area of circle A = 81π square inches

Now, we need to find 1/5 of the area of circle A for circle B:

Area of circle B = (1/5) * 81π
Area of circle B = 81π / 5
Area of circle B = 16.2π square inches

To get the numerical value of the area of circle B:
Area of circle B ≈ 16.2 * 3.14159
Area of circle B ≈ 50.868 square inches

Therefore, the correct answer is B. 50.868 in2.