Sine is opposite/hypotenuse. Opposite of angle
S is line
QR, which is unknown. Therefore start with the Pythagorean Theorem to find
QR. For simplicity, I'll use
x as a variable for
QR.

+60²=68²

=68²-60²

=4264-3600

=1024
x=

x=32
So
QR is 32. Therefore, sin
S is 32/68, which simplifies to 8/17.