Answer:
2/√5
Step-by-step explanation:
A unit circle is a circle of unit radius. This means that the radius of a unit circle is 1.
Let a represent the horizontal distance. Therefore the vertical distance = twice the horizontal distance = 2a
We can get the hypotenuse using Pythagoras theorem:
hypotenuse² = a² + (2a)²
hypotenuse² = a² + 4a²
hypotenuse² = 5a²
hypotenuse = √5a²
hypotenuse = a√5
sin(θ) = opposite / hypotenuse
sin(θ) = vertical distance / hypotenuse
sin(θ) = 2a / a√5
sin(θ) = 2/√5