Quick answer
A circle is the region inside a circumference. Every point on the circumference is the same distance from the center.
- Main formula
- Area = πr² and circumference = 2πr.
- Quick example
- Write the known measurements first, substitute them in the formula and keep the units.
Definition
A circle is the region inside a circumference. Every point on the circumference is the same distance from the center.
Main properties
- Radius is the distance from the center to the edge; diameter is twice the radius.
- Measurements must use the same unit before calculating.
- Draw a quick sketch to identify each value.
Formula
Area = πr² and circumference = 2πr.
Example method
Read the problem, mark the known measurements, choose the formula and simplify the result step by step.