Respuesta :

m<A + m<B + m<C = 180
80 + 3x + 5 + 5x - 1 = 180
8x + 84 = 180
8x =96
x = 12

m<
B = 3x + 5 = 3(12) + 5 = 41
m<C = 
5x - 1 = 5(12) - 1 =59
and 
m<A = 80

answer:

order from shortest to longest in ∆ABC

AC, AB, BC

P.S.
Smallest angle, shortest side.....
Largest angle, longer side....