What is the area of a sector with a radius of 8 and a central angle of [tex]\frac{5 \pi}{3}[/tex] radians?

A. [tex]\frac{320 \pi}{3}[/tex] units[tex]\(^2\)[/tex]

B. [tex]50 \pi[/tex] units[tex]\(^2\)[/tex]

C. [tex]\frac{140 \pi}{3}[/tex] units[tex]\(^2\)[/tex]

D. [tex]\frac{160 \pi}{3}[/tex] units[tex]\(^2\)[/tex]



Answer :

To find the area of a sector with a given radius [tex]\( r \)[/tex] and central angle [tex]\( \theta \)[/tex] in radians, we can use the formula for the area of a sector:

[tex]\[ \text{Area} = \frac{1}{2} r^2 \theta \][/tex]

where [tex]\( r \)[/tex] is the radius and [tex]\( \theta \)[/tex] is the central angle in radians.

Given:
- Radius, [tex]\( r = 8 \)[/tex]
- Central angle, [tex]\( \theta = \frac{5\pi}{3} \)[/tex] radians

Let's follow these steps to find the area of the sector:

1. Substitute the values into the formula:

[tex]\[ \text{Area} = \frac{1}{2} \cdot 8^2 \cdot \frac{5\pi}{3} \][/tex]

2. Calculate the values in the formula:

- First, calculate [tex]\( 8^2 \)[/tex]:
[tex]\[ 8^2 = 64 \][/tex]
- Next, substitute this value back into the formula:
[tex]\[ \text{Area} = \frac{1}{2} \cdot 64 \cdot \frac{5\pi}{3} \][/tex]

3. Simplify the multiplication:

- Multiply [tex]\( \frac{1}{2} \)[/tex] and [tex]\( 64 \)[/tex]:
[tex]\[ \frac{1}{2} \cdot 64 = 32 \][/tex]
- Now the formula becomes:
[tex]\[ \text{Area} = 32 \cdot \frac{5\pi}{3} \][/tex]

4. Complete the calculation:

- Multiply [tex]\( 32 \)[/tex] and [tex]\( \frac{5\pi}{3} \)[/tex]:
[tex]\[ 32 \cdot \frac{5\pi}{3} = \frac{160\pi}{3} \][/tex]

Therefore, the area of the sector is [tex]\(\frac{160\pi}{3}\)[/tex] square units.

Based on the given options, the correct answer is:

D. [tex]\(\frac{160 \pi}{3}\)[/tex] units[tex]\(^2\)[/tex]