Surface Area of Spheres Quick Check

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Question
Use the formula for the surface area of a sphere to find the surface area of a basketball that has a diameter of 9.2 inches. Use 3.14 pi and round your answer to the nearest hundredth, if necessary.(1 point)
Responses

84.64 in.2
84.64 inches squared

66.44 in.2
66.44 inches squared

265.77 in.2
265.77 inches squared

1,063.08 in.2

1 answer

To calculate the surface area of a sphere, you can use the formula:

\[ \text{Surface Area} = 4\pi r^2 \]

where \( r \) is the radius of the sphere.

  1. First, find the radius of the basketball. The diameter given is 9.2 inches, so the radius \( r \) is half of that:

\[ r = \frac{diameter}{2} = \frac{9.2}{2} = 4.6 \text{ inches} \]

  1. Now, substitute \( r \) into the surface area formula using \( \pi \approx 3.14 \):

\[ \text{Surface Area} = 4 \times 3.14 \times (4.6)^2 \]

  1. Calculate \( (4.6)^2 \):

\[ (4.6)^2 = 21.16 \]

  1. Now substitute this back into the formula:

\[ \text{Surface Area} = 4 \times 3.14 \times 21.16 \]

  1. Calculate \( 4 \times 3.14 = 12.56 \):

\[ \text{Surface Area} = 12.56 \times 21.16 \]

  1. Now multiply:

\[ \text{Surface Area} \approx 266.00 \text{ in}^2 \]

Rounding to the nearest hundredth, the surface area is approximately:

\[ \text{Surface Area} \approx 265.77 \text{ in}^2 \]

So the correct response is:

265.77 in.²