Question

How do I find an angle degree in a right triangle using cos, sin or tan? I have the opposite length and the adjacent. 2 for opp, 7 for adj. I did tan (B) = 2/7 but then I am stuck

Answer 1

15.945°

Explanation:

tan A = opp/adj

You are correct to use the tangent function.

You are also correct in writing

tan (B) = 2/7

You are not finding the tangent of a degree angle measure.

You are doing the opposite. You know what the tangent of an angle equals, and you need to find out the angle measure.

For that, you need to do the inverse tangent.

If you have a calculator, divide 2 by 7.

Then press the second function key followed by the tangent key.

The tangent key has "tan".

The second function on the tangent key is the inverse tangent, and its symbol is
`\tan^(-1)`.

In this case, the exponent -1 is not really an exponent. It really is function notation for the inverse function.

`\tan^(-1) (2)/(7) = 15.945^\circ`