What is the measure of the central angle of the sector whose area is 462 sq cm and radius of the circle is 21 cm?
Let central angle = $$\theta$$ and radius = 21 cm
Area of sector = $$\frac{\theta}{360} \times \pi r^2$$
= $$\frac{\theta}{360} \times \frac{22}{7} \times (21)^2 = 462$$
= $$\frac{\theta}{360} \times 22 \times 63 = 462$$
= $$\frac{\theta}{20} \times 77 = 462$$
=> $$\theta = \frac{462}{77} \times 20$$
=> $$\theta = 6 \times 20 = 120$$°
=> Ans - (D)
Create a FREE account and get:
