Unit 1, Lesson 6
Construction Techniques 4: Parallel and Perpendicular Lines
Geometry
Student Lesson Summary
When we write the instructions for a construction, we can use a previous construction as one of the steps. We now know two new constructions that are made up of a sequence of moves:
- Perpendicular lines are lines that meet at a 90 degree angle.
- Parallel lines are lines that don’t intersect. One way to make parallel lines is to draw 2 lines perpendicular to the same line.
Two figures of perpendicular lines. Figure on the left: Two congruent circles, each pass through the center of the other. A line through both centers extends beyond both circles. A blue line is drawn through the two circle's intersection points and a right angle is marked. The figure on the right is a pair of parallel lines with an intersecting blue line that is marked with two right angles.