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

m Ð a = 105⁰

m Ð b = 75⁰

m Ð c = 105⁰

m Ð d = 105⁰

m Ð e = 75⁰

m Ð f = 105⁰

m Ð g = 75⁰

Figure 1.30

Prove that is parallel to .

PR is a transversal to lines containing m Ð QPR = m ÐPRS
= 50⁰

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 .

Index

Introduction

1.1 Points, Lines and Planes
1.2 Line Segment
1.3 Rays and Angles
1.4 Some Special Angles
1.5 Angles made by a Transversal
1.6 Transversal Across Two Parallel Lines
1.7 Conditions for Parallelism

Chapter 2