Explain how to find the length of the side of any right triangle when you know two of the side lengths

You can use the pythagorean theorem
leg^2 + leg^2= hypotenuse^2

You have to add the two side lengths you know and subtract them from 190. 

Example:

The two sides of the triangle you know are 47° and 50°. 

47+50= 97

190-97= 93

In this example, the length of the side you don't know is 93.

Does this answer your question?