Trigonometry and Triangle

Question

Given a right angle triangle what formula is needed to find the missing angles and length ? also given the diagram of two triangle and asked to find the how long one side is what is the formula for that ? for example the letters KLM and STR  with l= 10 t =7  s = 9 and r =4 how would i find the length of K and the length of S please help with this 

Answer 1

I'm not sure that I understand the setup for triangles KLM and STR. A diagram might be helpful here. What I can tell you is that if you know the lengths of two sides of a right triangle, you can use the Pythagorean Theorem to find the length of the third side.