3. the formula to find the surface area of a sphere is to take the radius of the sphere and square it and multiply that amount by pi and then multiply that by 4. this is written algebraically as s=4πr 2 , where s is the surface area, r is the radius, and the value of π is 3.14. rewrite the equation to solve for the radius of the sphere if you know the sphere’s surface area. then estimate the radius of a sphere given a surface area of 500 meters2 .