Answer:
12.22
Explanation:
I think this is it, but double check using the other values now that we have 2 to work with.
Turn the triangle around to where HI is along the bottom. (Not necessary to solve, but easier to think about.)
We know Tan = Opp/Adj, and we know Opp = 11, and tan 42° = 0.90.
So, Tan(42°) = Opp/Adj
0.90 = 11/adj
Adj*0.90 = 11
Adj = 11 / 0.90 = 12.22 (rounded to 2 decimals.)
Check this by calculating sq. rt. hyp = 11^2 + 12.22^2, then see if that gives the other values.
And it does, sq.rt. of hyp = sq.rt. 270.32 roughly 16.44.
Cos = Adj/Hyp = 12.22/16.44 = .7433