To find the last angle, add the 90 degree angle and 65 degree angle.(155)
Since a triangle has a total of 180 degrees, subtract 155 from 180 to get the third angle.(25 degrees)
To find the last side, use the pythagorean theorem(a^2 + b^2 = c^2)
a^2 + 77^2 = 85^2
solve, and you'll get the last side