Q27 of 35 Page 311

The length of radius of a circular field is r meter. If the area of other circle is x times of first circle, let us see by calculating how length is of radius of other circle.

Given that the length of the circular field = r meter


The area of the circular field = πr2


Also, given that the area of the other circle = xπr2


We know that area of the circle = π(radius)2


Then, π ×(radius of other circle)2 = xπr2


⇒ (Radius of the other circle)2 = x r2


⇒ Radius of the other circle = r √x meter


More from this chapter

All 35 →
27

If the length of radius of a circular field was increased by 10%, let us write by calculating what per cent it increase the area of circular field.

 27

If the perimeter of a circular field was decreased by 50%, let us write by calculating what per cent it decreases the area of circular field.

 27

Let us calculate the area of a circular region circumscribe a triangle of which sides are 3 cm, 4 cm and 5 cm.

 27

Three circular plate were cut off from a tin plate with equal width if the ratio of length of diameter of three circles is 3:5:7, let us see by calculating the ratio of their weight.