Triangles
This is a polygon with three sides and three angles.
What is a triangle?
This quadrilateral can be called this even though this can have only 2 pairs of equal sides instead of 4 equal sides.
What is a rectangle?
These are the names you would use to classify a triangle with a right angle and only 2 equal sides.
What is a right triangle and an isosceles triangle?
This is a side sided polygon.
What is a hexagon?