# Constructing A Triangle With 3 Known Sides

How to construct a Triangle With 3 Known Sides

using just a compass and a straightedge

If you know the lengths of a triangles 3 sides, you can draw the triangle using a ruler and drafting compass

It is fun and easy to do.

In this example we are told the triangle has sides of **23**, **17** and **12** (press the play button):

images/construct.js?mode=tri3sides

(Note: this is not a classic "Construction" as we measured using a ruler.)