Using the formula for the area of a sector, solve for the area of a sector with an angle of 135° and a radius of 13 in.(1 point)

Responses

A=199.1 in.2
upper A equals 199.1 in. squared

A=398.2 in.2
upper A equals 398.2 in. squared

A=530.9 in.2
upper A equals 530.9 in. squared

A=30.6 in.2

1 answer

To find the area of a sector of a circle, we can use the formula:

\[ A = \frac{\theta}{360} \times \pi r^2 \]

where:

  • \(A\) is the area of the sector,
  • \(\theta\) is the angle in degrees,
  • \(r\) is the radius of the circle.

For this problem, we have:

  • \(\theta = 135^\circ\)
  • \(r = 13 , \text{in.}\)

Substituting the values into the formula:

\[ A = \frac{135}{360} \times \pi (13)^2 \]

Calculating \(r^2\):

\[ (13)^2 = 169 \]

Now substituting this value back into the equation:

\[ A = \frac{135}{360} \times \pi \times 169 \]

Calculating \(\frac{135}{360}\):

\[ \frac{135}{360} = \frac{15}{40} = \frac{3}{8} \]

So now we have:

\[ A = \frac{3}{8} \times \pi \times 169 \]

Using \(\pi \approx 3.14\):

\[ A \approx \frac{3}{8} \times 3.14 \times 169 \]

Calculating \(3.14 \times 169\):

\[ 3.14 \times 169 \approx 530.46 \]

Now multiply by \(\frac{3}{8}\):

\[ A \approx \frac{3}{8} \times 530.46 \approx 198.2 \]

So, approximately:

\[ A \approx 199.1 , \text{in}^2 \]

The answer is:

\[ A = 199.1 , \text{in}^2 \]

Thus, the correct response is:

A = 199.1 in.²