9514 1404 393
Answer:
Step-by-step explanation:
The distance can be calculated using the Law of Cosines. The angle internal to the triangle at Q is (180°-(146° -65°)) = 99°. Then the distance PR can be found from ...
 PR² = PQ² +QR² -2·PQ·QR·cos(∠PQR)
 PR² = 6² +10² -2·6·10·cos(99°) ≈ 154.77
 PR ≈ √154.77 ≈ 12.44 . . . . km
The distance PR is about 12 km.