Tentukan Nilai sin Q

Tentukan dulu nilai cos Q dgn aturan cosinus.
Cos Q= (p^2+r^2-q^2)/(2. P.r)
=(13^2+15^2-8^2)/(2.13.15)
=(169+225-64)/2.13.15
=330/390
=11/13
Sin Q = V(13^2-11^2)/13 = V(169-121)/13
= V48/13=4v3/13
Jawaban A