We know that the triangles are similar.
We can use proportions to solve
a 16
----- = -------
10 20
This is found by using the ratios of the similar sides
Using cross products to solve
20*a = 16*10
20a = 160
Divide each side by 20
20a/20 = 160/20
a = 8
We can do the same for side by
b 16
---- = -------
15 20
Using cross products to solve
20b = 16*15
20b =240
Divide each side by 20
20b/20 = 240/20
b = 12
