| __ | 21. | Chord | | A. | Distance across a circle, going through the center |
| __ | 22. | Circumference | | B. | Distance all the way around a circle |
| __ | 23. | Congruent | | C. | A flat, 2-d surface |
| __ | 24. | Diameter | | D. | A line that touches a circle, but doesn't go through |
| __ | 25. | Pi | | E. | Distance from the middle of a circle to circle |
| __ | 26. | Plane | | F. | Ratio between the circumference and the diameter |
| __ | 27. | Radius | | G. | The same shape |
| __ | 28. | Secant | | H. | a line inside of a circle whose endpoints are on the circle |
| __ | 29. | Tangent | | I. | A line going through a circle |
| __ | 30. | Vertex | | J. | An angular point |