Let the radius of the sphere be r cm.

We know that, surface area of a sphere = 4πr²

Given, surface area of a sphere is 5544 cm²

⇒ 4πr² = 5544

⇒ 4× × r ² = 5544

⇒ r² = 441

⇒ r = 21 cm

Thus diameter = 42 cm