Geometry Puzzle

4. proof / A type of proof that uses boxes and arrows to show the flow of a logical argument
5. angles / Two angles that have the same measure
6. of reflection / A line that acts as a mirror for a reflection
11. / The distance around a circle
15. / A chord that contains the center of a circle
16. / When a point from two figures is the same distance from each figure
17. / A statement that can be proven
18. / A statement that contains the phrase "if and only if"
20. / A real number that corresponds to a point on a line

1. / A set of points consisting of two different rays that have the same endpoint
2. / The point that divides a segment into two congruent segments
3. / The point of concurrency of the lines containing the altitudes of a triangle ]
7. lines / Coplanar lines that do not intersect
8. angles / Two angles that share a common vertex and side, but have no common interior points
9. / The point of concurrency of the three medians of a triangle
10. / The side opposite the right angle of a right triangle
12. angles / Two angles whose measures have a sum of 90 degrees
13. / A line that intersects a circle in two points
14. angles / Angles of a polygon
19. point / The starting point of a vector