I am not sure if it is the best but heres one way to do it
After this step, find the button on your calculator that says 'tan' and type n 30 degrees, then press enter or the equal sign or whatever button you press to calculate.
You should get that tan(30) = 0.5774
Now plug that back into the equation
(approximated)
Hope that helps!
A=65
B=-75
C=-3
D=0
E=20,000
F=95
G=12
H=-12