The mnemonic SOH CAH TOA helps you remember that
... Sin = Opposite/Hypotenuse
The side opposite angle K is marked with length 5. The hypotenuse KM is marked with length 10. Using the above relationship ...
... sin(∠K) = 5/10 = 1/2
The first choice is appropriate: [tex]\dfrac{1}{2}[/tex]
