Geometry - Proofs Vocabulary

5. An angle whose measure is greater than 90 degrees.
10. The opposite of division.
13. An angle whose measure is less than 90 degrees.
15. Lines that meet at a 90 degree angle are ___________.
17. 5x = 6y is the same as 6y = 5x by the ____________ property of equality.
19. If ½ (4x – 10y) = 14, then 2x – 5y = 14 by the ____________ property.
20. If P, Q, and R are colinear, and R is between P and Q, then PR + RQ = PQ. This is the _____________ Addition Postulate.
21. An angle ____________ divides an angle into two equal parts.
22. Right angles are exactly __________ degrees.

1. Two angles with a common side but no common interior points are ________.
2. If 2x + 7 = 15, then 2x = 8 by the _____________ property.
3. You always start a proof with the ____________.
4. If m<D + m<C = 90, then <D and <C are ____________ angles.
6. Two nonadjacent angles formed by two intersecting lines are __________ angles. (Hint: they are across from each other)
7. Segments of equal lengths are ________ segments.
8. If a = b and b = c, then a = c by the _____________ property of equality.
9. If m<A + m<B = 180, then <A and <B are ___________ angles.
11. A ___________ ___________ forms a straight line and is also supplementary.
12. In <ABC, point B is the __________.
14. Two lines that will never intersect
16. AB = AB by the ______________ property of equality.
18. The middle point of a line segment.