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

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

A=398.2 in.2

1 answer

To find the area of a sector, you 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, and \( r \) is the radius.

Given:

  • \( \theta = 135^\circ \)
  • \( r = 13 \) inches

Substituting the values into the formula:

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

First, calculate \( 13^2 \):

\[ 13^2 = 169 \]

Now substitute that back into the formula:

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

Next, simplify \( \frac{135}{360} \):

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

Now substituting this back:

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

Now calculate the area:

\[ A \approx \frac{3}{8} \times 3.14159 \times 169 \approx \frac{3}{8} \times 530.1436 \approx 198.0364 \]

Now to round to one decimal place:

\[ A \approx 198.0 , \text{in}^2 \]

From the options provided, the closest one is:

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

Thus, the answer is:

A = 199.1 in².