## Parallel and Perpendicular Lines

#### The object of this lab is for students to use pairs of parallel and
perpendicular lines on transparencies to discover facts about their slopes.

Instructions to the teacher:

1. Review finding the slope of a line by counting rise/run on a graph.

2. Provide each pair of students with 1 sheet of graph paper and 2 small
squares

of a transparency sheet. Each transparency square should be prepared
ahead

of time with either 2 parallel or 2 perpendicular lines.

3. Students place 1 square on top of the graph paper rotating until neither
line is

horizontal or vertical. Then count each slope and record the slopes
as well as

whether the lines are parallel or perpendicular. Repeat this process
2 more

times by rotating the transparency on the graph paper.

4. Repeat with the second square.

5. Discuss their findings.

It may be helpful to put a table on the board similar to the one below: