Question

What is the diameter of a circle whose area is equal to the sum of the areas of two circles of diameters 10 cm and 24 cm?

Answer 1

Area of circle = Area of circle of diameter 10 cm + Area of circle of diameter 24 cm

or Area of circle = Area of circle of radius 5 cm + Area of circle of radius 12 cm

πr² = π(5)² + π(12)²

πr² = 25 π + 144π = 169π

r = 13 So, required diameter is 26 cm.