# Trigonometry of the right triangle

#### paul_alan

Joined Nov 5, 2011
43
I'm a new Biomedical Tech student and we're working with Trigonometry of the right triangle right now and I have a problem I can't figure out: If a = x, c = 2x : find the Sine, Cosine and Tangent for angles a and b. How do you determine the value for x?

#### hgmjr

Joined Jan 28, 2005
9,029
This appears to be a homework question. If you can confirm this I will move it to the Homework forum.

How about attaching a scan of your effort to solve the problem so that we can see where you are getting snagged.

hgmjr

#### 1chance

Joined Nov 26, 2011
46
You are focusing on the wrong issue. It doesn't matter what x is. What matters is the ratio of a to c. Sin A = a/c (opp/hyp) or in your case x/2x =>1/2. To find the value of angle A simply use inverse sin of 1/2. You should be aware that sin A = cos B as they are an example of a cofunction. Once you have determined the value of angle A you can use the calculator to find each value (approximated) OR draw the triangle out & use pythagorean's theorem to find the missing side b (letting a = 1 and c= 2 remember everything is proportional) and then you will have the exact values. Obviously, if you want to work with Angle B, it is equal to 90 - Angle A or just use the cofunctions. The big idea in this problem is seeing that Sin A = 1/2.

#### jimkeith

Joined Oct 26, 2011
540
By inspection, it is obviously a 30°, 60°, 90° triangle--take it from there

#### 1chance

Joined Nov 26, 2011
46
Yes, this is obvious. But you gave him the fish--I was trying to teach him how to fish! #### jimkeith

Joined Oct 26, 2011
540 Woops--blew that one--at least, I hope he never forgets this one...