Answer:
Answer is 60 degrees.
Step-by-step explanation:
We know that in a right angled triangle if one leg is 1, and hypotenuse is 2,
then other leg = 
(By using Pythagorean theotrem)
Now consider a right angle triangle with hypotenuse 2 and one leg 1, and the angle between other leg and hypotenuse.
Since sin 30 = 1/2 we have cos 60= sin (90-60) = 1/2
Hence sin 60 = rt 3 /2
Using the above we get sin inverse of quantity square root of three divided by two is 60 degrees.