In this set, we'll be talking about the relationship between the size, shape of a grid and the number of quadrilaterals.
First, we have to know what is a quadrilateral and what is a grid.
Quadrilateral is a polygon with 4 sides and 4 vertices.
Grids are shapes made by multiple congruent quadrilaterals aligning together, commonly squares. In this set, we'll all be using grids made with squares. Originally, it should be called grid of squares, but we'll just call it grid for short.
All grids have a size, in this set, all sizes of a grid are denoted as \(a\times b\) where \(a\) is the length of the grid, and \(b\) is the height of the grid.
For example, the left diagram above shows a \(5\times 5\) grid, \(a=b=5\), the right diagram above shows a \(4\times 3\) grid, \(a=4\), \(b=3\).
The variables \(a\) and \(b\) will be frequently used in the following pages.
This is one part of Grids and Quadrilaterals.