The corresponding sides of two similar triangles are . The corresponding angles of two similar triangles are .

if the corresponding sides of two similar triangles have congruent angles than the sides correspond to each other 
in triangle abc
and triangle def 
ab:de
bc:ef
ca:fd
so they correspond in ratio but are not necessarily congruent
if in the similar triangles the sides are equal than the angles will correspond in ratio to add up to 180 degrees
so if triangle abc≈ triangle def
then
∠abc:∠def
∠bca:∠efd
∠cab:∠def