A wire in the shape of a circle of radius 28 cm is bent in the form of a square. What is the difference of their areas?
(Take $\pi =\frac{22}{7}$)
Answer & explanation
Correct answer: option 4
We know that,
Area of the circle = πr2
Area of the square = side × side
Circumference of the circle = 2πr
Perimeter of square = 4 × side
Circumference of the circle = Perimeter of the square
= 2 π × 28 = Perimeter of square
Perimeter of square = 8 × 22 = 4a
Side of the square ‘a’ = 44 cm
Area of square = 44 × 44 = 1936 cm2
Area of the circle = \(\frac{22}{7}\) × 28 × 28 = 2464 cm2
Difference of the areas = 2464 - 1936 = 528 cm2