Two Column Proof Definition:
This consists of a list of statements, and the reasons that we know those statements are true. The two column proof has five parts:
1) Given
2) Proposition
3) Statement Column
4) Reason Column
5) Diagram
Two Column Proof Example 1:
Given: ∠A and ∠B are complementary∠A ≅ ∠C
Prove: ∠A and ∠C are supplementary
| Statement | Reason |
|---|---|
| ∠A and ∠B are complementary | Given |
| m∠A + m∠B = 90° | Def. of Complementary Angles |
| ∠A ≅ ∠C | Given |
| m∠A ≅ m∠C | Def. of Congruent Angles |
| m∠C + m∠B = 90° | Substitution Property of Equality |
| ∠C and ∠B are complementary | Def. of Complementary Angles |
