Every one has his/her own counting strategy when counting the number of geometry shapes.
Below are some common strategies.
- For simple shapes, an easier way is to permute all the combination.
Example 1
1. How many different line segments can you count in the following figure?3
- For more complex shapes, a good idea is to first figure out the pattern and then counting (calculating) based on the pattern.
Example 2
1. How many different line segments can you count in the following figure?28
Example 3
2. How many triangles can you count in the following figure?56
3. How many rectangles can you count in the following figure?30
Hint:(1 + 2)(1 + 2 + 3 + 4)