please help with this question

We know that [tex]\sin(45)=\cos(45)[/tex] and this is the only point when sin and cos are equal lengths. Because both [tex]\sin(45),\cos(45)=\dfrac{\sqrt{2}}{2}[/tex]
Now if the sin of 30° is a half that would mean that cos of 60° is also a half.
Hope this helps.
r3t40