The diameter of a circle is equal to the perimeter of a square whose area is 3136 cm2 . What is the circumference of the circle ?

Answer: Option B

Area of square = 3136 cm²
Side of squared = $$\sqrt{3136}$$   = 56 cm
Perimeter of square :
= 4a
= (4 × 56) cm
= 224 cm
= diameter of circle
∴ Circumference of circle :
$$\begin{array}{rl}& =\pi d\\ & =\frac{22}{7}\times 224\\ & =704\text{ cm}\end{array}$$