Im pretty sure that's a right triangle.
A shape with three and only three sides is a triangle, but it is not possible for a triangle to have three perpendicular sides.
A hexagon.
Hexagon.
triangle.
Not possible. The shape will either be incomplete or have intersecting lines.
How about a triangle which is a 2 dimensional shape with 3 sides
No but 2 of its 3 sides are equal in lengths.
No but it does have 3 sides 2 of which are of equal lengths.
square
2 equilateral triangles
An isosceles triangle
My Guess is a hexagon