In the given figure lines l and m are parallel.
m<5=38 and m<6=62.
The sum of angles are 38+62=100
<3 and 100 degrees (m<5+m<6) are lying on the same side of transversal and hence are supplementary angles for the parallel lines.
<3+100=180( supplementary angle property)
m<3=180-100(subtracting 100 both sides)
m<3=80
The right answer is 80 .