### 26.7.2 Isosceles triangles in the plane

See Section 27.6.2 for isosceles triangles in space.

The isosceles_triangle command creates isosceles triangles.

- isosceles_triangle takes three mandatory arguments and one optional argument:
  - a,b, two points.
  - θ, an angle.
  - Optionally, var, a variable name.
- isosceles_triangle(a,b,θ ⟨,var⟩) returns and draws the isosceles triangle abc, where ab and ac are equal sides and θ is the angle between ab and ac.

  With the argument var, c will be assigned to var.

#### Examples

isosceles_triangle(i,1,-3*pi/4)

isosceles_triangle(i,1,-3*pi/4,C)

normal(affix(C))

−

√

2

+i