I don't understand what's being asked for finding theta

Question

I don't understand how to find theta when given the hypotenuse and a decimal. I understand that .866 was found by a fraction, but how do I find that fraction?

Given the following information, solve for the missing value. (Round to the nearest degree.)

Given: sin θ = 0.8660

hypotenuse = 0.25

Find: θ =      

Answer 1

Given: sin θ = 0.8660

hypotenuse = 0.25

Find: θ = 60° or π/3 using arcSin(0.866)

This is a 30 60 90 triangle.

I always remember this and also Sin 30° = 1/2

0.866 = (√3)/2