# Perpendicular and Parallel Lines 1.5

#### Time Frame

1 class periods of 30 minutes each

Marcia Kloempken

### Summary

Students will recognize perpendicular and parallel lines.

### Materials

Students will need:

• pencil
• colored pencils or pens
• metric ruler
• protractor
• scissors

### Background for Teachers

Knowledge of perpendicular and parallel lines.

### Instructional Procedures

#### Attachments

Notes on definitions.
Examples
Activity
Students need to take out all of the above materials.

1. Draw a line segment that is 9cm long. Label the endpoints A and B.
2. Beginning at A, draw a line segment perpendicular to AB that is 5 cm long.Label the endpoint C.
3. Beginning at B, draw a line segment perpendicular to AB that is 5cm long and on the same side of AB as AC. Label the endpoint D.
4. Draw CD.
• Which two segments are parallel?
• Which segments are perpendicular?
• What is the angle between AB and AC?
• Is this true for all angles between the perpendicular lines?
• If AB is 9cm, how long is CD?