Answer:
a) 23.56 ft (2 dp)
b) 58.90 ft² (2 dp)
Step-by-step explanation:
Formula
[tex]\textsf{Arc length}=r \theta[/tex]
[tex]\textsf{Area of a sector}=\dfrac{1}{2}r^2 \theta[/tex]
[tex]\quad \textsf{(where r is the radius and}\:\theta\:{\textsf{is the angle in radians)}[/tex]
Calculation
Given:
- [tex]\theta=\dfrac{3 \pi}{2}[/tex]
- r = 5 ft
[tex]\begin{aligned}\implies \textsf{Arc length} & =r \theta\\& = 5\left(\dfrac{3 \pi}{2}\right)\\& = \dfrac{15}{2} \pi \\& = 23.56\: \sf ft\:(2\:dp)\end{aligned}[/tex]
[tex]\begin{aligned} \implies \textsf{Area of a sector}& =\dfrac{1}{2}r^2 \theta\\\\ & = \dfrac{1}{2}(5^2) \left(\dfrac{3 \pi}{2}\right)\\\\& = \dfrac{25}{2}\left(\dfrac{3 \pi}{2}\right)\\\\ & = \dfrac{75}{4} \pi \\\\& = 58.90 \: \sf ft^2\:(2\:dp)\end{aligned}[/tex]
