Subject: equilateral triangle

Name: Peggy

Who is asking: Teacher
Level: Elementary

Please send directions to make an equilateral triangle in plane geometry. I want each student to draw two, cut them out, and place them together to form a Jewish Star. We are beginning the reading of Number the Stars.

Hi Peggy,

The directions I have use a compass so, depending on the age of your students, you may want to make the triangles yourself and have the students trace around them.

Draw a line that is the length that you want for a side of the triangle. I have called the ends of the line P and Q in the diagram below. Put the point of the compass at P and open the compass so that the pencil is at Q. With this setting on the compass and the compass point at P draw an arc of a circle above the line.

Without changing the setting on the compass move the point to Q and draw an arc which intersects the arc you already drew.

Join P and Q to the point of intersection to form an equilateral triangle.

If you don't have a compass that is large enough you can make do with some string with one end tied around a pencil.

I hope this helps,
Go to Math Central