Question

I need help finding out what shapes are Triangles or Quadrilaterals! Help me!

Answer 1

Quadrilaterals have 4 sides, and triangles have 3 sides. So, you simply have to count the number of sides. 

Answer 2

Triangles are anything with three vertexes and three angles to it and are always closed.

Quadrilaterals are anything with four vertexes and four angles on them and are always closed.  Examples include a square, rectangle, trapezoid etc.