Question

Find the diameter of a circle whose circumference is 77​

Answer 1

We are given that the circumference of a circle is 77 units and we need to find it's diameter . But let's recall that for any Circle with radius r , the circumference is given by 2πr . And diameter is double of radius i.e d = 2r , so we can write the circumference as 2r(π) i.e dπ . So , now here

${:\implies \quad \sf d\pi =77}$

${:\implies \quad \sf d\times \dfrac{22}{7}=77}$

${:\implies \quad \sf d=\dfrac{77\times 7}{22}}$

${:\implies \quad \sf d=\dfrac{\cancel{11}\times 7\times 7}{\cancel{11}\times 2}}$

${:\implies \quad \sf d=\dfrac{49}{2}}$

${:\implies \quad \bf \therefore \quad \underline{\underline{Diameter=24.5\:\: units}}}$