Question

A smaller circle passes through the center of, and is tangent to, a larger circle. The area of the smaller circle is 9 square units. What is the area of the larger circle in square units?

Answer 1

Area of bigger circle = 36.32cm²

Explanation:

Kindly find attached rough sketch for your reference

This problem bothers on the mensuration of flat shapes, a circle

Kindly find attached

Given data

Area of small circle =9cm³

Say we assume the all unit is in cm

From the diagram we can see that the diameter of the small circle is the radius of the bigger circle

So let us solve for the diameter of the small circle

9= πr²

r²=9/3.142

r²= 2.86

r=√2.86

r= 1.7cm

But diameter of small circle

d= 2r

d= 1.7*2= 3.4cm

Hence the radius of the bigger circle is 3.4cm

Area of bigger circle =πr²

=3.142*3.4²

=3.142*11.56

Area of bigger circle = 36.32cm²