Question

Which equation finds the value of x in the triangle below?
http://media.education2020.com/evresources/3111-13-05/mc006-1.jpg

Answer 1

do you have a grasp of sin, cos and tan in a right angled triangle?

You know 2 angles (including the right angle) and 1 side - so you can solve it using
sin, cos or tan of 20 deg

Answer 2

I'm afraid that this is a fundamental concept - if you do not know what sin, cos and tan are then you must look it up in your study notes.

In essence, for a right angled triangle, the ratio of any two sides to each other defines one of the trig functions (sin cos or tan) Find out those relationships - this question requires you to understand them - if I give you the answer you will be no nearer understanding this essential mathematical concept

Answer 3

http://en.wikipedia.org/wiki/Trigonometric_functions