Use a special right triangle to write sin 30º as a simplified fraction.

This is a right angled triangle with hypotenuse length 2 and the legs are of length 1 and sqrt3.

the 2 angles other than 90 degrtees are 30 and 60 degrees.

The 30 degree angle is opposite the leg of length 1 so it's sine

is opp/hyp = 1 / 2