See section 12.8.4 for equilateral triangles in the plane.
The equilateral_triangle command takes as arguments three points, A, B and P.
equilateral_triangle returns and draws the equilateral triangle
ABC, where C is in the same half plane as
P.
Input:
then:
Output:
triangle_rectangle can take an optional fourth argument,
which is a variable which will be assigned to the third vertex of the
triangle.
Input:
then:
Output: