Sort into categories unique triangles not unique triangles (many triangles) and no triangles(impossible)

Answer 1

Unique triangles:
- Equilateral triangle
- Isosceles triangle
- Scalene triangle

Not unique triangles (many triangles):
- Right triangle
- Acute triangle
- Obtuse triangle

No triangles (impossible):
- A polygon with more than three sides
- A shape with sides that do not connect to form a closed figure