26.15.6 Checking whether an object in the plane is an isosceles triangle
See Section 27.11.10 for checking for isosceles
triangles in 3D geometry.
The is_isosceles
command determines whether or not a geometric object is an isoceles triangle.
-
is_isosceles takes
G, a geometric object or a sequence of three points assumed to be
the vertices of a triangle.
- is_isosceles(G) returns 1,2 or 3 if the object
is an isoceles triangle (the number indicates which vertex is on two
equal sides), returns 4 if the object is an equilateral triangle,
and returns 0 otherwise.
Examples
| T:=isosceles_triangle(0,1,pi/4); is_isosceles(T) |
| T:=isosceles_triangle(0,1,pi/4,C); is_isosceles(T[0]) |
Note that T[0] is a triangle since T is a list made
of a triangle and the vertex C.
| is_isosceles(1+i,-1+i,-i) |
| is_isosceles(0,2,1+i*sqrt(3)) |