Question

,,,,,,,

Answer 1

if you know two sides and an angle, then yes (although you might have two choices)

Answer 2

sometimes there is an "ambiguous case" when using the law of sines
here is a picture of two different triangle that have the same angle and also two sides of the same length

Answer 3

i don't know because i don't know what the actual question is

Answer 4

if I only know some of the side lengths of a *right* triangle?

There are only 3 sides, so if you know "some of the sides" that means 2?
Anyway, you can use pythagoras to find the 3rd side of a right triangle if you know the other 2.

And you can use trig to find all the angles and sides, if you know 2 sides, or one side and 1 angle (other than the 90 degree angle)