Finding the Area of a Circle Using Circumference

This video tutorial teaches how to find the area of a circle using its circumference. It begins by reviewing the formulas for area and circumference, highlighting a common mistake of using diameter instead of radius. The tutorial then demonstrates how to correctly calculate the area using examples, including one with an approximated value of pi. By the end, viewers will understand how to derive the area from circumference accurately.

What is the correct formula to find the area of a circle if you know the diameter?

• Area = pi times diameter squared

• Area = pi times radius squared

• Area = 2 times pi times diameter

• Area = pi times diameter

How do you find the radius from the diameter?

• Multiply the diameter by 2

• Divide the diameter by 2

• Subtract 2 from the diameter

• Add 2 to the diameter

In the example of the playground, what is the radius if the circumference is 18 pi yards?

• 36 yards

• 6 yards

• 9 yards

• 18 yards

If a circle has a circumference of 37.68 cm and pi is approximated as 3.14, what is the diameter?

• 18 cm

• 6 cm

• 24 cm

• 12 cm

What is the area of a circle with a radius of 6 cm using pi approximated as 3.14?

• 113.04 cm squared

• 36 cm squared

• 72 cm squared

• 18 cm squared