Circles

3. length: The linear distance along a curved line between two points
5. A straight line segment from the center of a circle or sphere to its perimeter, or the length of that segment
7. angle: An angle that has its vertex on the circle's edge.
8. A straight line segment that passes through the center of a circle or sphere, with both endpoints resting on the edge of that shape
9. angle: The angle formed at the center ofCentral angletween two radii.
11. A line that intersects the circle's line twice
13. A line that's outside the circle and touches the circle once
15. arc: The longest curved path connecting the same two points on a circle.

1. A line segment whose endpoints are on the circumference of the circle
2. arc: The shortest curved path connecting two points on a circle
4. the total distance around the outside edge
6. formula: πr2
10. a fundamental mathematical constant defined as the ratio of a circle’s circumference to its diameter.
12. angle: An angle that has its vertex at the center of the circle
14. The total amount of two-dimensional space enclosed by its boundary (circumference)