Example 1
Lines l and m are parallel and line n is the transversal find the measures of angles a, b, c, d, e, f and g.
Figure 1.29
Solution :
m Ð a = 105^{0}
m Ð b = 75^{0}
m Ð c = 105^{0}
m Ð d = 105^{0}
m Ð e = 75^{0}
m Ð f = 105^{0}
m Ð g = 75^{0}
Example 2
Figure 1.30
Prove that
is parallel to
.
Solution :
PR is a transversal to lines containing m Ð QPR = m ÐPRS = 50^{0}
Since they are alternate interior angles
is parallel to .
Therefore Ð SRT and Ð
RTU are supplementary angles formed by the transversal TR on line containing
. Therefore
is parallel
to . It
is already shown that
is parallel to
. Therefore
is parallel to
.
**********
