Circumference and Area of a Circle
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 parts of circles - Answers
1. The answer
The area of the shape is units .
(Note that we could also multiply 3 by to get units .)
2. The answer
The area of the semicircle is units .
(Note that we could also multiply by to get units .)
3. The answer
The area of the semicircle is units .
(Note that we could also multiply by to get units .)
4. The answer