Question

Find the area of a sector of a circle of radius 21cm and central angle 120 degrees

Answer 1

Answer:

154 cm²

Step-by-step explanation:

$\text{Area of sector:} = \dfrac{\theta}{360} \times \pi r^2\\\\\underline{\text{Given:}}\\\\\rightarrow \text{Radius} = 21 \: cm\\\\\rightarrow \text{Central Angle} = 120\°\\\\\text{Substituting in the formula, we get}\\\\\implies \text{Area of Sector:} = \dfrac{ 120 \°}{360 \°} \times \dfrac{22}{7} \times 21 \times 21\\\\\implies \text{Area of Sector:} = \dfrac{1}{3} \times 22 \times 3 \times 7\\\\\\\implies \text{Area of Sector:} = \dfrac{462}{3}$

$\bf{\textbf{Area of Sector}= 154 \:cm^2}$

Answer 2

=120/360×22/7×21^2

=1/3×22/7×21×21

=22×21

=462sq.cm