Geometry construction using a compass and straightedge

This page shows how to construct an
equilateral triangle
with compass and straightedge or ruler. An equilateral triangle is one with all three sides the same length. It begins with a given
line segment
which is the length of each side of the desired equilateral triangle.

It works because the compass width is not changed between drawing each side, guaranteeing they are all
congruent
(same length). It is similar to the
60 degree angle construction, because the
interior angles
of an equilateral triangle are all 60 degrees.

Click here for a printable worksheet containing an ellipse drawing problem.
When you get to the page, use the browser print command to print as many as you wish. The printed output is not copyright.

Try it yourself

Click here for a printable worksheet containing two problems to try.
When you get to the page, use the browser print command to print as many as you wish. The printed output is not copyright.