You can't. One side and one angle is never enough to define a unique triangle.
If the side opposite the right angle is 150mm, the other 2 sides could be . . .
-- 75 and 129.9
-- 100 and 111.8
-- 110 and 101.98
-- 120 and 90
-- 130 and 74.83
-- both 106.07
or any one of an infinite number of other possibilities.
You need to know one more side, or one more angle.
