Question

if radius of a circle is increased to twice its original length how much will the area of circle is increased?​

Answer 1

Answer:

let us assume that the radius of the circle is r.

then,          area of circle (1st circle)=πr^2

and,           area of circle(2nd circle)(after doubling the r)

                  =π(2r)^2

                  =π*4r^2=π4r^2

to find by how much the circle has increased in area we should find its ratio

therefore,   π4r^2/πr^2 =4

therefore,the circle has increased in area by 4 times.

Answer 2

Now, area of circle =π(2r)2=4π. Therefore, the area of circle is increased by 4 times.