Since this is a right triangle, we know c = 90. The sum of a+b must also be 90, since a+b+c = 180
A = 1ft, C = 3ft. B is unknown. We can calculate B using the pythagorean theorem.
1^2 + b^2 = 3^2
1 + b^2 = 9
b^2 = 8
b = 2sqrt2
Angle a = 1/3 = about 19.5 degress
Angle b = 2sqrt2/3 = 70.5 degress
Angle c = 90 degrees
