Triangle.
A shape with three sides is called a triangle.
triangle...
-3
isoseles triangle
A cube...
A pyramid.
an equilateral triangle.
A shape with three linear sides and one curved side can be drawn, but such a shape has no specific name.
A triangle as no other 2d shape can have 3 sides.
There is no shape that is made up 3 sides that is not a triangle. Any shape that is made up of 3 sides is classified as a triangle no matter what shape or size it is.
A scalene triangle
An irregular hexagon