Write a single formula for area that will work for a rectangle, a parallelogram, a trapezoid, a triangle, and a square. Explain how it works.

First of all I'll tell you about a, b and h. They are the symbols I will use to show you how to get the same formula for a square, rectangle, triangle, parelellogram, and a trapezoid. A trapezoid in Australia is called a trapezium. A is the parallel line from the base. The base is b. H is the height to a at a right angle from the base.I got these symbols from starting on the trapezoid. a can be zero.

The formula is .5 times h times{b+a}.

{ } means brackets. I'll put numbers to letters.

Square=.5*4*{4+4} = 16 h b a
Rectangle=.5*4*{6+6} = 24
Triangle= .5*4*{6+0} = 12
Paralellogram=.5*4*{6+6} = 24
Trapezoid=.5*4*{6+3} = 18