Need help this is for civics

so maybe a i hope

Explanation:

During the war some 16 million Americans served in the United States Armed Forces, with 405,399 killed and 671,278 wounded. There were also 130,201 American prisoners of war, of whom 116,129 returned home after the war.

Fewer than one percent of Americans are in the military, compared with about nine percent during World War II. Researchers say that's helped create a divide between veterans and non-veterans

i believe it d) heterogeneous

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