A fun and useful area and perimeter 2D shape tutorial and interactive activities for you whiteboard. Learn how to find the area and perimeter of rectangles and triangles and then complete the questions.
http://ictmagic.wikispaces.com/Maths
In this article provides the simple tricks with formulas to find the number of triangles for the following figures
* Counting triangles with in Square, Rectangle, Quadrilateral
* Number of possible triangles within a triangle
http://www.allmathtricks.com/number-triangles/