A university would like to create a circular eating area with picnic tables. The eating area will have small plants that form a path to create individual sections that are sectors. The angle formed by the plants is [tex]$\theta=120^{\circ}$[/tex], and the radius is [tex]$r=9\,m$[/tex]. Find the area of each sector.

A. [tex]$A=3 \pi\,m^2$[/tex]
B. [tex][tex]$A=6 \pi\,m^2$[/tex][/tex]
C. [tex]$A=27 \pi\,m^2$[/tex]
D. [tex]$A=54 \pi\,m^2$[/tex]



Answer :

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

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

where:
- [tex]\( r \)[/tex] is the radius of the circle,
- [tex]\( \theta \)[/tex] is the central angle of the sector in radians.

Given:
- The radius [tex]\( r = 9 \)[/tex] meters,
- The central angle [tex]\( \theta = 120^\circ \)[/tex].

First, we need to convert the angle from degrees to radians. The conversion factor between degrees and radians is given by:

[tex]\[ \theta_{\text{radians}} = \theta_{\text{degrees}} \times \frac{\pi}{180} \][/tex]

So for [tex]\( \theta = 120^\circ \)[/tex]:

[tex]\[ \theta_{\text{radians}} = 120^\circ \times \frac{\pi}{180} = \frac{2\pi}{3} \][/tex]

Now, substitute the radius and the angle in radians into the area formula:

[tex]\[ A = \frac{1}{2} \times 9^2 \times \frac{2\pi}{3} \][/tex]
[tex]\[ A = \frac{1}{2} \times 81 \times \frac{2\pi}{3} \][/tex]
[tex]\[ A = \frac{1}{2} \times 81 \times \frac{2\cdot\pi}{3} \][/tex]
[tex]\[ A = \frac{81}{1} \times \frac{\pi}{3} \][/tex]
[tex]\[ A = 81 \times \frac{\pi}{3} \][/tex]
[tex]\[ A = \frac{81 \pi}{3} \][/tex]
[tex]\[ A = 27 \pi \text{ square meters} \][/tex]

Therefore, the area of each sector is:

[tex]\[ 27 \pi \text{ square meters} \][/tex]

So, the correct answer is:

C. [tex]\( A = 27 \pi \text{ m}^2 \)[/tex]