I’ve been trying so hard, provide reasons for the proof.

given: angle 2=4
and 2 and 3 are supplementary
prove: angle 1=3

statement: reason
1. < 2 =~< 4. given
2. m< 2=m< 4 angle congruence postulate
3. < 2 and < 3 are supplementary given
4. m< 2+m< 3=180 degrees definition of supplementary angles
5. < 1 and < 4 are supplementary fill in blank
6. m< 1+m< 4=180 degrees definition of supplementary angles
7. m< 1+m< 4=m< 2+m< 3 fill in blank
8. m< 1+m< 4=m< 4+m< 3 fill in blank
9. m< 1=m< 3 fill in blank
10. < 1=~< 3 fill in blank