# Math

## Circles

### Glossary

• Unit circle: Circle with centre at $$(0, 0)$$ and a radius of 1
• Circle: Set of all points a given distance from a point
• Radius: Any line segment that connects a point on the circle to the centre
• Tangent line: A line that intersects only a single point on the circle
• Seacant line: A line that intersects two points on a circle
• Chord: :A line segment between two points on a circle
• Diameter: A chord that goes through the centre of a circle. Length of a diameter is equal to $$radius * 2$$
• Arc: Connecting two points on a circle.
• Minor arc: The shortest way around the circle connecting two points
• Major arc: The longest way around the circle connecting two points
• Circumference: Length of the circle from a point all the way around back to itself; or the length of a major arc between one point and itself
• $$\pi$$ / Pi: A constant of approx 3.14. It is the ratio between the circumference and the diameter of a circle
• Circumference & $$\pi$$: The circumference of a circle is $$\pi2r$$ $$\pi = \frac{circumference}{diameter}$$, $$circum. = \pi diameter$$, $$c = \pi2r$$