this is a triangle with angles A, B, and C.
we know that A+B+C=180
A:B:C = 3:4:8
split 180 into 15 parts. One part is 12 degrees. Now
apply the proportions to the smallest angle (A)
A=3*12 = 36
(B=4*12= 48)
(C=8*12= 96)
The measure of the smallest angle is A=36 degrees