A circle has a radius of 16 cm . Find the area of a sector if θ=72° .

(1 point)
Responses

A=51.2π cm2A=51.2π cm2

A=256π cm2 A=256π cm2

A=204.8π cm2 A=204.8π cm2

A=3.2π cm2 A=3.2π cm2

1 answer

To find the area of a sector of a circle, 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 of the sector in degrees,
  • \( r \) is the radius of the circle.

Given:

  • \( r = 16 \) cm,
  • \( \theta = 72^\circ \).

Now, we substitute the values into the formula:

\[ A = \frac{72}{360} \times \pi (16)^2 \]

First, calculate \( (16)^2 \):

\[ (16)^2 = 256 \]

Then substitute this back into the area formula:

\[ A = \frac{72}{360} \times \pi \times 256 \]

Now, simplify \( \frac{72}{360} \):

\[ \frac{72}{360} = \frac{1}{5} \quad \text{(since 72/72 = 1 and 360/72 = 5)} \]

Now we have:

\[ A = \frac{1}{5} \times \pi \times 256 \]

Calculating that:

\[ A = \frac{256\pi}{5} \]

Now, perform the calculation:

\[ \frac{256}{5} = 51.2 \]

So, the area of the sector is:

\[ A = 51.2\pi , \text{cm}^2 \]

Thus, the correct answer is:

A=51.2π cm²