For this activity, we cut an orange in half making two hemispheres. We took one hemisphere and traced as many circles as we could onto our sheet and then took the orange peel and took small pieces to see how much of the orange peel would fit into the circumference of the orange. I learned the formula for a surface are of a sphere is 4 πr2. By taking the circumference of the orange, the peel filled 4 circles which means that the circumference is multiplied by 4.