Circumference and Area of a Circle
Completion requirements
To calculate the circumference (which is like perimeter) and the area of a circle, you need a special irrational number: pi. Pi is the ratio of the circumference of a circle to its diameter. Watch this lecture series to explore the circumference and area of circles, and complete the interactive exercises.
Practice
Area of a circle - Answers
1. \(A \approx 25 \pi\)
\(A \approx 78.5 unit ^{2}\)
2. \(A=16 \pi\)
3. \(A=25 \pi\)
4. \(A \approx 1 \pi\)
\(A \approx 3.14\) unit \(^{2}\)
5. \(A=4 \pi\)
6. \(A=4 \pi\)
7. \(A \approx 9 \pi\)
\(A \approx 28.26\) unit \(^{2}\)
