## Geometry Across the Curriculum

I use geometric drawing across the curriculum in several projects.  Below is an in-progress shot of an 8th-grader's design for a stained glass window, an assignment from my medieval history unit that incorporates symbolism along with geometric design. In world history, we use geometric drawing when studying Roman and Islamic mosaics, and students have the … Continue reading Geometry Across the Curriculum

## Construct a Hexagon

The construction for a regular hexagon is a favorite of my students every year and the one most of them choose as a basis for their geometric design project.  We are simply going to begin with a line and use our compass to draw three congruent circles along it.  Start with the center circle. Mark … Continue reading Construct a Hexagon

## Bisect a Segment

Today we'll be doing a very simple construction -- bisecting a segment.  In other words, we will be cutting a line segment in half.  Begin by drawing matching circles from your two endpoints (A and B).  The radius of the circle is not important.  As long as it is more than half the length of … Continue reading Bisect a Segment

## Identify Geometric Shapes

Here's a little activity to wrap up our geometry study for the week.  Have your students consider the following drawing and try to identify as many polygons as they can.  If they need a little guidance, here are some possibilities... regular hexagons rectangles parallelograms rhombi other irregular quadrilaterals a multitude of triangles -- equilateral, isosceles, … Continue reading Identify Geometric Shapes

## Copy Any Polygon

We can employ the two skills we've been working on this week -- constructing congruent segments and constructing congruent angles -- to create a copy of any polygon.   Use a straight edge to draw any polygon.  Here's an irregular hexagon drawn for me by a helpful eighth-grader and his ruler:   To copy your … Continue reading Copy Any Polygon

## Construct Congruent Angles

Today we'll be looking at another basic construction: congruent angles.  You can use this construction to copy any angle without using a protractor to measure. Begin with the angle you would like to copy. Draw any ray.  This will act as the baseline for your new angle.  The vertex (V) of your original angle will … Continue reading Construct Congruent Angles

## Geometric Drawing

This week, the big kids are working on their geometric constructions, mathematical drawings achieved with the use of only a compass and an unmarked straight edge. This is one of my favorite units to teach.  Mathematics in general is an incredibly beautiful discipline that explores patterns and the natural order of the universe.  While those … Continue reading Geometric Drawing