Remember "SOH CAH TOA"
Sine = (Opposite/Hypotenuse)
Cosine = (Adjacent/Hypotenuse)
Tangent = (Opposite/Adjacent)
1st Problem:
Remember that cosine is (Adjacent/Hypotenuse). And also know that we are using inverse trig (regular trig solves for sides, inverse solves for angles.)

2nd Problem:
For this we are using Cosine (Adjacent/Hypotenuse) to solve for the adjacent side. Your equation will look like this:

For this, all you need to do is cross multiply, and your answer will be

3rd Problem:
So this is actually a special triangle. Because its an isosceles right triangle, it follows the 45-45-90 rule, which is if one of the legs is x, then the other leg is also x and the hypotenuse is x√2.
In this case, EF is going to be 16√2, or 22.63 cm, because 1. for the hypotenuse to not have √2 means that the leg does. Remember that √2(√2) = 2, which means that we would need to know what times 2 makes 32, which is 16.
4th Problem:
So for this we will be using the pythagorean theorem, which is
. In this case, the equation is going to be

Firstly, solve the exponents:

Next, combine 225 and 361 together:

Lastly, square root each side, and your answer should be

5th Problem:
So you'll be using the pythagorean theorem like before, except with new numbers and your solving for one of the legs.

Like before, solve the exponents:

Next, subtract 361 on both sides:

Lastly, square root both sides, and your answer should be
