Parallel Lines 12

Table of Contents

• Lines Parallel to the Same Line
• Summary
• What’s Next?

In the previous segment, we learnt the Consecutive interior angles test and its converse. In this segment, we will learn a corollary based on parallel lines.

Lines parallel to the same line

This corollary states that, if two lines are parallel to the same line, then they are parallel to each other.

If line m || line l and line n || line l, then, line m || line n.

Fig. 1

Given:

1. line m || line l
2. line n || line l
3. line o intersects line l, line m, and line n at points I, J, and K respectively.

Fig. 2

To Prove: line m || line n

Proof:

1

line l || line m

Given