Geometric Proofs 4/14/22

What is the first step in a geometric proof as presented in class?

What is the second step in a geometric proof as presented in class?

What is the third step of a geometric proof as presented in class?

$$Line\ AB\ \parallel\ Line\ CD$$

What does the symbol in middle between Line AB and Line CD?

$$Line\ AB\ \perp\ Line\ CD$$  

What does the symbol between Line AB and Line CD means?

Given: E is the midpoint of line DF.

Conclusion: DE = EF.

State the proof

Given: $$m\angle WXY\ =50\degree$$   

Conclusion: $$\angle WXY$$  is an acute angle.

State the proof

(a)  

Given: $$\angle GAT$$  = $$\angle BAT$$   are vertical angles.

Conclusion: $$m\angle GAT$$  = $$m\angle BAT.$$  

State the proof.

(a)  

Given: x + y = $$90\degree$$  

Conclusion: y = $$90\degree$$  - x

State the proof.

(a)  

Can a postulate from algebra be used as a justification in geometry?