Question

COSINE LAW: Solve triangle PQR. round angles to the nearest tenth​

Answer 1

Answer:

Hi,

Step-by-step explanation:

PR²=PQ²+QR²-2*PQ*QR*cos(51°)

=15²+12²-2*15*12*cos(51°)

=142,444659....

PR=11.9350...

PQ²=QR²+PR²-2*QR*PR*cos(R)

cos(R)=(12²+142.444...-15²)/(2*12*11.9350...)=0,21451112....

angle R=77,61315...°≈77.6°

angle P=180°-51°-77.6°≈51,4°