Given: ∠4 is an exterior angle of ΔABC . Prove: m∠1 + m∠2 = m∠4

Picture: https://s.yimg.com/tr/i/4516dabcf9a74411afddd9977b5028ee_A.png

Statements:

1. ∠4 is an exterior angle of ABC

2. ∠3 and ∠4 form a linear pair

3. ∠3 is supplementary to ∠4

4. m∠3 + m∠4 = 180*

5. ? (my answer: m∠1 + m∠2 +m∠3 = 180*)

6. m∠1 + m∠2 + m∠3 = m∠3 + m∠4

7. ? (My answer: m∠1 + m∠2 =m∠4)

Reason:

1. ? (my answer: Given)

2. ?

3. ?

4. ? (My answer: Linear pair)

5. Triangle Sum Theorem

6. ? (my answer: Substitution)

7. ? (my answer: either subtractive of addition property of equality)

Sorry if this a lot but I'm really struggling with geometry and would like it if someone could help. Please help me.

Guest Nov 17, 2017