Question

The radii of two circles are 19 cm and 9 cm respectively. Find the radius and area of the circle which has its circumference equal to the sum of the circumferences of the two circles..

Answer 1

Radius of the first circle = 19 cm 

Circumference of first circle = 2πr 

= 2π × 19 cm 

Radius of second circle = 2πr 

= 2π × 9 cm 

Total circumference = 2π × 19 + 2π × 9 

= 2π (19+9) 

= 2 x \(\frac{22}7\times28\) = 176 cm

2πr = 176

r = \(\frac{176\times7}{2\times22}\) = 28 cm

Area of circle = \(\frac{22}7\times28\times28\)

= 2464 cm²