Prove identity (5.25) by negating the upper index in vandermonde's convolution (5.22). then show that another negation yields (5.26).

Check the attached file for the solution.

You have 2 sides that are 2 cms and you have 6 sides that are 1/2 cm and you have 4 sides that are 1 cm. the smallest sides are 1/2 the medium sized sides are 1 and the smallest are 1/2. so to find the perimeter you have to add them all up together so your answer will be 11 cm's

The first one is 2/3the second is 1/160the third is 4/125