1. The problem is to find the formula for the surface area of a sphere. 2. The formula for the surface area $A$ of a sphere with radius $r$ is: $$A = 4\pi r^2$$ 3. This formula comes from the fact that a sphere is a perfectly symmetrical 3D shape, and its surface area depends on the square of its radius. 4. To use this formula, you need to know the radius of the sphere. 5. For example, if the radius $r = 3$, then: $$A = 4\pi (3)^2 = 4\pi \times 9 = 36\pi$$ 6. So the surface area is $36\pi$ square units. This formula is important because it helps calculate how much material is needed to cover a spherical object or how much surface is exposed.