The purpose of this lesson is to give students practice writing and following precise instructions with straightedge and compass moves as they create interesting designs. In the previous lesson, students learned how to use the straightedge and compass. In subsequent lessons, students will use properties of constructions to make arguments. In this lesson, students attend to precision when they refer to figures in their construction using mathematical terms and labeled points (MP6).
In the cool-down, the steps students follow will construct a parallel line. This is the first set of instructions they see for lines that do not intersect, but students will come up with another construction to create lines that are parallel after they have learned to construct perpendicular lines.
The patterns in the launch of the “Make Your Own” activity are used with permission from the author.
If students have ready access to digital materials in class, they can choose to perform all construction activities with the GeoGebra Construction tool accessible in the Math Tools or available at https://www.geogebra.org/m/VQ57WNyR.
- Create a construction from instructions (in written language).
- Describe (in writing) construction steps precisely.
- Let’s use compass and straightedge constructions to make patterns.
- I can follow instructions to create a construction.
- I can use precise mathematical language to describe a construction.
A circle of radius \(r\) with center \(O\) is the set of all points that are a distance \(r\) units from \(O\).
To draw a circle of radius 3 and center \(O\), use a compass to draw all the points at a distance 3 from \(O\).
A set of points on a line with two endpoints.
Two lines that don't intersect are called parallel. We can also call segments parallel if they extend into parallel lines.