This construction produces an isosceles triangle given the length of the legs and the apex angle (the one at the top). The construction proceeds in two main steps:
The above animation is available as a printable step-by-step instruction sheet, which can be used for making handouts or when a computer is not available.
|1||Angles BAC and QPR are congruent||By construction. See Copying an angle with compass and straightedge.|
|2||Line segments FG, PQ and PR are congruent||All drawn with the same compass width.|
|3||PQR is an isosceles triangle with the given apex angle and leg length.||An isosceles triangle is a triangle with two congruent legs. See Isosceles triangle definition.|