First you have to use the Pythagorean theorem to find the lenght of c which is called the hypotenuse(that is the side opposite the right angle and is always the longest side of a right triangle)

c2 = a2 + b2 
c2 = 12 + 12 
c2 = 1 + 1 
c2 = 2   ↔  c = √2
Based on what you learned from the writting the trig functions for the 30oand 60o angles write the 6 trig functions for a 45o angle