Question

A wire in a shape of a circle of radius 28 cm is bent in the form of a square. What is the difference of their areas? (Take \(\pi = \frac{22}{7})\)
1. 538 cm²
2. 530 cm2
3. 532 cm2
4. 528 cm2

Answer 1

Correct Answer - Option 4 : 528 cm2

Given :

Radius of wire is 28 cm. 

Concept used :

Area of the circle = π radius²

Area of the square = side × side 

Circumference of the circle = 2π × radius 

Perimeter of square = 4 × side 

Calculations :

Circumference of the circle = Perimeter of the square (Length will remain same) 

⇒ 2 π × 28 = Perimeter of square 

Perimeter of square = 8 × 22 

So , 

Side of the square = 44 cm 

Now, 

Area of square = 44 × 44 

⇒ 1936 cm²

Area of the circle = π × 28 × 28 

⇒ 2464 cm²

Difference of the areas = 2464 - 1936 

⇒ 528 cm²

∴ Option 4 will be the correct answer.