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.
