Surface Area of a Sphere

In todays activity was to use the peelings of a spherical orange to determine the formula to find the surface area. First we had to cut it in half, trace the circumference as many times as needed, then peel the half oranges and fill as many circle fully with peelings. As a result, 4 circles were filled giving me the conclusion that >>
Area of Sphere could = 4 x (pi) x diameter.

However, this is what I assume.