sin^-1(0.669)
First, Identify the quadrant in which the angle could be. Since the value of sine is positive we know that it would be located in the first and second quadrant.
Then we are going to convert the decimal value to a fraction value. 0.669 is equal to 669/1000. We know that sine is the ratio of side opposite a given angle to the hypotenuse. Therefore our triangle must be:
Using the pythagorean theorem we find that: