Identify and define the Reconstruction Amendments. Why were they significant?

the perimeter of a triangle is 69 cm. side a is 5 cm shorter than side b. side c is twice as long as side a. find the length of each side. i need to know how to do it in 2 equations.  

equations:

a = b-5

c = 2a

a + b + c = 69

to replace ineffective because   andrew jackson's spoil system was a deliberate policy after he became president to remove federal employees he considered to be political opponents and replace them with his own supporters.