a = 5
b = 3
C = 90 degrees ( right angle)
Apply pythagorean theorem to find c:
c^2 = a^2 + b^2
c^2 = 5^2 + 3^2
c^2 = 25 + 9
c^2 = 34
c = √34
c= 5.83
Now, apply Trigonometric functions:
Sin A = opposite / hypotenuse
Sin A = a / c
Sin A = 5/ 5.83
A = arc sin (5 /5.83 )
A = 59.05°
All of the interior angles of a triangle add up to 180°
A + B + C = 180°
59.05 + B + 90 = 180
B= 180 -59.05 - 90
B= 30.95°