Question

The length of a rectangle is \(\frac{3}{5}\) of the radius of a circle. The radius of a circle is equal to the side of a square whose area is 4900 m². What is the area of the rectangle if its breadth is 20 m.
1. 840 m²
2. 860  m²
3. 480 m²
4. 880 m²

Answer 1

Correct Answer - Option 1 : 840 m²

Given:

Area of a square = 4900 m2 

The radius of a circle = Side of the square 

Length of rectangle = 3/5 of the radius of the circle

Breadth of rectangle = 20 m 

Formulas used:

Area of square = (Side)²

Area of rectangle = Length × Breadth 

Calculation:

Area of square = (Side)²

⇒ 4900 =  (Side)2

⇒ Side = √4900 

⇒ Side = 70 m 

Radius of the cirlce = Side of the square = 70 m 

Length of rectangle = 3/5 × 70 m 

⇒ Length of rectangle = 42 m 

∴ Area of the rectangle = 42 m × 20 m 

⇒ 840 m²