Sometimes we need to find the area of a circle and sometimes we need to find the circumference. Write at least three real-world situations for each. Explain what measurements would need to be made in each situation and how area or circumference would be found.

One situation would be a round flowerbed. The edge would have bricks around it, and you’d need the circumference for that. You’d measure the diameter of the circle, and multiply that by pi.
Circumference = (pi)(diameter)

A first for area is the same flowerbed but filling it in with mulch around the flowers. For that, you’d take 1/2 the diameter to find the radius. Area = (pi)(radius)^2

A second for circumference is measuring a distance traveled by a wheel. If you needed to measure distance from one point to the next, and you know you have a 16 inch wheel, you can measure how many rotations of that will go from point A to point B. Calculate the circumference, multiply that by how many toes the wheel rotated for that distance, and you know how far you traveled.

A second for area is figuring out how much cake batter you would put in a round cake pan. If you have a 9 inch cake pan, the radius is 4.5 inches. Area = (pi)(4.5)(4.5)

A third for circumference is to figure out how much curb material you would use to pave the edge of a dead-end street. It might only be a 1/2 circle, but then you calculate the circumference and divide by half.

A third for area is calculating the area of a pizza. Most restaurants tell you how many inches the pizza is, which is the diameter. Divide that in half and calculate the area.

Do this last one with friends and say that whoever calculates the area first doesn’t have to pay for their share of the pizza. (No one would really do that, but it might make your math teacher smile)