GeomEtric SHAPES ON THE PLANE_1  
Section: Geometry  
1. THE AREA OF A SQUARE  
The
formula to find the area of a square is You can use the following window to help you check the formula. 


2. THE AREA OF A RECTANGLE  
The formula to find the area of a rectangle
is AREA= side_a·side_b=a·b 

1. Give side a a fixed value, e.g. 3. Change the length of side b and note that the area of the rectangle form the 3 times table. Can you explain the reason for this? The Greeks used the area of a rectangle as a geometric interpretation to help them with multiplication!

3. THE AREA OF A PARALLELOGRAM  
The formula to find the area of a
parallelogram is AREA= base·height=b·h This formula is demonstrated below. The parallelogram ABCD has the same area as a rectangle with sides b and h. As we already know how to work out the area of a rectangle we can say that the area of a parallelogram is b·h. 

1. Now copy the demonstration with a piece of paper and a pencil. 
Agustín Muñoz Núñez  
Spanish Ministry of Education. Year 2001  
Except where otherwise noted, this work is licensed under a Creative Common License