1 ) It is given that ,
l // m , transversal p
a = 78° ( corresponding angles )
2 ) p//q , transversal is m
a = d = 78° ( corresponding angles )
b = d = 78° ( vertically opposite angles )
3 ) l//m , transversal q
c + d = 180° ( sum of angles same side of the
transversal are supplementary )
c + 78° = 180
c = 180 - 78
c = 102°
Therefore ,
a = b = d = 78°
c = 102°