Question

What is the approximate circumference of a circle with a diameter of 40 inches? (careful you need radius so 40/2)

(Use π = 3.14)

|C= 2 *π*r|

(A.) 125.6 in.

(B.) 63 in.

(C.) 251 in.

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Answer 1

Result: Circumference = 125.6 in.

Step-by-step explanation:

Step 1

First, we need to find the radius, r

To find the radius, all we need to do is divide the diameter by half

40 / 2 = 20

r = 20

Step 2

Now, we need to find the circumference, C

To find the circumference, let's use this formula:

C = 2 x r x 3.14

Substitute:

C = 2 x 20 x 3.14

Multiply:

2 x 20 = 40

40 x 3.14 = 125.6

Answer 2

A) 125.6 inches

Step-by-step explanation:

1. The radius: As you said, it is half the diameter, so it is 40/2, which is 20 inches.

2. Plug in numbers into the equation: r = 20 inches, π = 3.14

C = 2 * 3.14 * 20 inches (of course, it was unnecessary to find the radius when we already have the diameter, but this was done to fit the given equation)

Multiply: C = 125.6 inches