Answer:
a) 19.63 ft (2 dp)
b) 147.26 ft² (2 dp)
Step-by-step explanation:
To find the length of the curved fence, use the formula for arc length of a circle.
To find the area of the vegetable garden, use the formula for area of a sector of a circle.
Formula
[tex]\textsf{Arc length}=2 \pi r\left(\dfrac{\theta}{360^{\circ}}\right)[/tex]
[tex]\textsf{Area of a sector}=\left(\dfrac{\theta}{360^{\circ}}\right) \pi r^2[/tex]
[tex]\quad \textsf{(where r is the radius and}\:\theta\:{\textsf{is the angle in degrees)}[/tex]
Calculation
Given:
- [tex]\theta[/tex] = 75°
- r = 15 ft
[tex]\begin{aligned}\implies \textsf{Arc length} &=2 \pi (15)\left(\dfrac{75^{\circ}}{360^{\circ}}\right)\\ & = 30 \pi \left(\dfrac{5}{24}\right)\\ & = \dfrac{25}{4} \pi \\ & = 19.63\: \sf ft\:(2\:dp)\end{aligned}[/tex]
[tex]\begin{aligned} \implies \textsf{Area of a sector}& =\left(\dfrac{75^{\circ}}{360^{\circ}}\right) \pi (15)^2\\& = \left(\dfrac{5}{24}\right)\pi \cdot 225\\& = \dfrac{375}{8} \pi\\& = 147.26\: \sf ft^2 \:(2\:dp)\end{aligned}[/tex]
