Idon't understand trig at all can someone just explain how to do anyone of these

SOH CAH TOA 
s = opposite/ hypotenuse c= adjacent/hypotenuse t= opposite/adjacent

the side opposite from the angle is the " opposite "
the longest side is the "hypotenuse" 
the side thats left over is the adjacent

for example for question one: 
the given angle is 38 with a given opposite length of 12.5 so if you are trying to figure out the hypotenuse you'd plug into the calculator sin(38)12.5  this would give you the length of the hypotenuse. if you are trying to find the adjacent angle you would use tan(38)12.5 i hope this helps. i loved learning trigonometry in geometry!

Maybe the answer is 20mm. all i really did was just multiply, which is obvious.

Ithink is a. true, but not sure