Let's go through each question one by one to derive the formulas and calculate the areas.
Question 1
The formula for the area of a sector is given by:
\[ A = \frac{\theta}{360°} \times \pi r^2 \]
The correct response is: Divide the measurement of the sector’s angle by 360°, then multiply the quotient by π times the radius squared.
Question 2
Given:
- Angle \( \theta = 75° \)
- Radius \( r = 4 \) ft
Using the formula for the area of a sector:
\[ A = \frac{75}{360} \times \pi \times (4)^2 \] \[ A = \frac{75}{360} \times \pi \times 16 \] \[ A = \frac{75 \times 16}{360} \times \pi = \frac{1200}{360} \times \pi = \frac{10}{3} \pi \approx 10.472 \text{ ft}^2 \]
The correct response is: A=10.472 ft.²
Question 3
Given:
- Angle \( \theta = 135° \)
- Radius \( r = 13 \) in
Using the formula for the area of a sector:
\[ A = \frac{135}{360} \times \pi \times (13)^2 \] \[ A = \frac{135}{360} \times \pi \times 169 \] \[ A = \frac{135 \times 169}{360} \times \pi = \frac{22815}{360} \times \pi \approx 63.375 \pi \approx 199.1 \text{ in}^2 \]
The correct response is: A=199.1 in.²
Question 4
Given:
- Radius \( r = 6 \) in
- Angle \( \theta = 120° \)
Using the formula for the area of a sector:
\[ A = \frac{120}{360} \times \pi \times (6)^2 \] \[ A = \frac{120}{360} \times \pi \times 36 \] \[ A = \frac{120 \times 36}{360} \times \pi = \frac{4320}{360} \times \pi = 12 \pi \text{ in}^2 \]
The correct response is: A=12π in.²
Question 5
Given:
- Radius \( r = 15 \) ft
- Angle \( \theta = 180° \)
Using the formula for the area of a sector:
\[ A = \frac{180}{360} \times \pi \times (15)^2 \] \[ A = \frac{1}{2} \times \pi \times 225 \] \[ A = \frac{225}{2} \times \pi = 112.5\pi \text{ ft}^2 \]
The correct response is: A=112.5π ft.²
Summary
- Divide by 360° for area of sector.
- A=10.472 ft.²
- A=199.1 in.²
- A=12π in.²
- A=112.5π ft.²