Equilateral Triangle

There are several ways to construct an equilateral triangle. This version comes straight out of Euclid’s Elements!

Scroll down to step through the instructions.

01. Start with a line. The length of this line will determine the length of each of the sides of the equilateral triangle.

02. Fix your string or rope at one end of this line and extend it to the other end of the line. Rotate the free end around the fixed end, marking as you go to draw a circle.

03. Repeat step 02, this time starting from the other end of the line.

04. Identify the ends of the starting line as well as one of the points of intersection between the two circles.

Draw lines connecting each of these points.

05. You have drawn an equilateral triangle!