Area of a Sphere
February 28, 2020
Grade 9s are working on understanding how to calculate surface are and volume these days. Today’s activity shows how to calculate the surface area of a sphere.
We measured an orange, and drew 5 or 6 circles with the same diameter.
We then peeled the orange and filled the circles, like a jigsaw puzzle.
We can always fill 4 circles with the peels. We know already how to calculate the surface area of a circle, A=(pi)(r)^2, so the surface area of a sphere is A=4(pi)(r)^2.
No comments yet