Answer:
H = -6
Step-by-step explanation:
In trigonometry, to solve right triangles, we use sine, cosine, and tangent (their definitions, and the laws of sine and cosine) to help us fill in the blanks. Do you need more information (I'm rusty on law of sines and law of cosines, but pretty fresh on definitions and identities).
Surface are is length times height.
8*8=64
a cube has 6 sides
64*6=384
The answer on the picture is right