Question:
What is the area of a sector of a circle of radius 5 cm formed by an arc of length 3.5 cm?
Solution:
We have
$r=5 \mathrm{~cm}$
length of the $\operatorname{arc}(l)=3.5 \mathrm{~cm}$
Now we will find the area of the sector.
Area of the sector $=\frac{1}{2} \times l r$
Substituting the values we get,
Area of the sector $=\frac{1}{2} \times 3.5 \times 5$...(1)
Now we will simplify the equation (1) as below,
Area of the sector $=\frac{1}{2} \times 17.5$
Area of the sector $=8.75$
Therefore, area of the sector is $8.75 \mathrm{~cm}^{2}$