Question

What is the measure of angle A in the triangle below?

Answer 1

You can use any of the trig functions for this.
Do you know sine or cosine or tangent?

Answer 2

yes

Answer 3

well pick your favorite one and set up the ration and do the division

Answer 4

err ratio, not ration

Answer 5

check out the Kahn Academy trig videos... the first one is great
and look at the unit circle while you are there
best 7 minutes I have ever seen explaining trig functions