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=30.6 in.2
upper A equals 30.6 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=199.1 in.2
upper A equals 199.1 in. squared

1 answer

To find the area of a sector, you can use the following formula:

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

where:

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

Given:

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

Plugging in the values:

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

Calculating \( r^2 \):

\[ 13^2 = 169 \]

Now substituting that into the formula:

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

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

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

Now substituting that back in:

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

Now calculate:

\[ A \approx \frac{3}{8} \times 3.14159 \times 169 \approx \frac{3}{8} \times 530.143 \approx 199.3 , \text{in}^2 \]

Thus, the area of the sector is approximately:

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

The correct answer is:

A = 199.1 in²