- Define geometric construction
- Copy a given line segment using only a compass and a straightedge
Introduction to Constructions: Compass and Straightedge
The word construction in geometry has a very specific meaning: the drawing of geometric items such as lines and circles using only a compass and straightedge. A compass is a drawing tool that can be used to measure distances and draw arcs and circles. An arc is a piece of a circle.
We make constructions in geometry using a compass and a _________________________.
Compasses come in different forms. These are some examples and drawings of compasses. You can also see an arc in the last two pictures:
A straightedge can be anything with straight edge, like an index card. The important thing to remember with constructions is that you are not allowed to measure angles with a protractor or measure lengths with a ruler.
Construction: How to Copy a Line Segment
1. Fill in the blank: A construction is a geometric drawing made with only a ________________________________ and a __________________________________.
2. Copy the line segment seen below using the steps you learned to make a construction. If you don’t have the tools to do it, write the steps you would take to copy it.