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: