Triangle congruence proofs, step by step
A proof is a chain of statements, each resting on a reason.
The question
Given AB ≅ AD; CB ≅ CD
Prove △ABC ≅ △ADC
| Statements | Reasons |
|---|---|
| 1. AB ≅ AD | Given |
| 2. CB ≅ CD | Given |
| 3. AC ≅ AC | Reflexive Property |
| 4. △ABC ≅ △ADC | ? |
Reason for step 4: GivenReflexive PropertyVertical AnglesAlternate Interior AnglesDefinition of MidpointSSSSASASAAASHLDefinition of Perpendicular
Which reason completes the proof?
Which reason completes the proof?
Step 4:△ABC ≅ △ADC
△ABC ≅ △ADC→SSS
SSS
- The proof is missing the reason for step 4: "△ABC ≅ △ADC". Read what that step claims.
- Three pairs of sides are now known equal, and three sides fix a triangle: SSS.
- So the missing reason is SSS.
How it works.
- 01
The proof is missing the reason for step 4: "△ABC ≅ △ADC". Read what that step claims.
- 02
Three pairs of sides are now known equal, and three sides fix a triangle: SSS.
- 03
So the missing reason is SSS.