he triangles are similar. Find the value of a.

bout side of triangle is 16 and 20 and the other triangle is a and 8

A. 10
B. 6
C. 16
D. 12

Im thinking it 12

16/20=a/8

a= 16*8/20=.....128/20=6.4 about 6

I am wondering if the problem should have read 16 and 20 and the other triangle is 8 and a.
That gives a=10