Making more stick patterns

This task is about using ice block sticks to make patterns and finding a rule for the pattern.
a)  Use your sticks to make shape 1 of the pattern below.
     Add the correct number of sticks to make shape 2 and then shape 3.
 
b)  Add the correct number of sticks to make shape 6 of the pattern.
     Draw these shapes in the space below.
 
shape 1                           shape 2                                    shape 3     
                                  
 
    shape 6
 
 
 
 
 
 
 
c)  Write the number of sticks you used for each shape on the table below.
     The first two have been done for you.
 
Shape Number of sticks
1 6
2 10
3  
... ...
7  
10  
15  
 
d)  Describe a rule that helps you work out the number of ice block sticks needed for any shape number?
     For example, write a rule that would help work out how many sticks are neeed to make Shape 100.