What is the radius of a sphere which area is equal to the sum of the areas of four circles of radius 7?

radius = 7 units

Step-by-step explanation:

Given:

Radius = 7 units

Find area of 4 circles:

1 circle = π (7) ² = 49π units²

4 circles = 49π x 4 = 196π units²

Find radius of sphere:

4πr² = 196π

r² = 49

r = 7