Question

Given the following diagram, find the required measures.

Given: l | | m

m 1 = 120°
m 3 = 40°

m 5 =

40
60
120

Answer 1

I would use "opposite interior angles are equal"
which means , in this problem, <5 equals <2
so if you can find <2 , you know <5
and finding <2 is like the problem you just did: two angles add up to a straight line.
that is: <1 + <2 = 180