Step-by-step explanation:
Supplementary angles are angles that have the sum of their angles to be 180°. Hence if <1 and <2 are supplements, then <1+<2 = 180°.... 1
Similarly if <3 and <4 are supplements, then <3+<4 = 180° ....... 2
Equating the left hand side of both equations since they are both equal to 180°, we will have;
<1+<2 = <3+<4 ....... 3
From the question we are told that <1 = <4, substituting this condition into equation 3;
From 3; <1+<2 = <3+<4
<4+<2 = <3+<4 (since <1 = <4)
subtract <4 from both sides
<4+<2 -<4= <3+<4 -<4
<2 = <3 (Proved!)
