Don't be thrown off by the cone. This is really just a triangle problem. To solve it, we need a little bit of trigonometry knowledge:
SOH-CAH-TOA
You should say this aloud to yourself until you've got it memorized. It stands for:
Sine = Opposite/Hypotenuse
Cosine = Adjacent/Hypotenuse
Tangent = Opposite/Adjacent
When you see a problem that requires this knowledge, write it down that you've got it all straight.
Now, if you're looking for the measure of the angle θ, you need to determine what the sides are relative to this angle.
The side that measures 5 inches is adjacent to the angle. The side that measures 7 is opposite the angle. Now, using SOH-CAH-TOA, we can see that the function we'll use is tangent.
So now we can put the measures of the sides into the tangent equation to get our answer:
