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=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

A=30.6 in.2

1 answer

The area \( A \) of a sector of a circle can be calculated using the formula:

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

where \( \theta \) is the angle of the sector in degrees, and \( r \) is the radius of the circle.

Given:

  • \( \theta = 135^\circ \)
  • \( r = 13 \) in.

Let's substitute the values into the formula:

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

First, calculate \( (13)^2 \):

\[ (13)^2 = 169 \]

Now substitute this into the area formula:

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

Now simplify \( \frac{135}{360} \):

\[ \frac{135}{360} = \frac{135 \div 45}{360 \div 45} = \frac{3}{8} \]

Now we can write the formula as:

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

Next, calculate \( A \) using \( \pi \approx 3.14159 \):

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

Calculating \( 3.14159 \times 169 \):

\[ 3.14159 \times 169 \approx 531.8 \]

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

\[ A \approx \frac{3}{8} \times 531.8 \approx 199.1 \]

Thus, the area of the sector is approximately:

\[ \boxed{199.1 \text{ in}^2} \]

The correct response is:

A = 199.1 in.².