Question

the area of a semicircle field is 77cm
${?}^{2}$
find its perimeter

Answer 1

Answer:

147.71 cm

Step-by-step explanation:

$\text{Area of semicircle = \dfrac{1}{2} \times \pi \times r^2 = 77 \: cm^2 }\\\\\\\implies \dfrac{1}{2} \times \dfrac{22}{7} \times r =77 \\\\\\\implies r = \dfrac{2 \times 7 \times 77}{22}\\\\\\\implies r = \boxed{49 \: cm}\\\\\\\text{Now, circumference of semi-circle = \pi r = \dfrac{22}{7} \times 49 }\\\\\\= \large \underline{\boxed{\boxed{\bold{147.71 \: cm}}}}$

Hope it helps.