Answer:
Distance between P and R is 40.15 km.
Step-by-step explanation:
From the picture attached,
Petrol kiosk P is 12 km due North of another petrol kiosk Q.
Bearing of a police station R is 135° from P and 120° from Q.
m∠QPR = 180° - 135° = 45°
m∠PQR = 120°
m∠PRQ = 180° - (m∠QPR +m∠PQR)
= 180° - (45° + 120°)
= 180° - 165°
= 15°
Now we apply sine rule in ΔPQR to measure the distance between P and R.
[tex]\frac{\text{sin}(\angle QPR)}{\text{QR}}= \frac{\text{sin}(\angle PQR)}{\text{PR}}=\frac{\text{sin}\angle PRQ}{\text{PQ}}[/tex]
[tex]\frac{\text{sin}(45)}{\text{QR}}= \frac{\text{sin}(120)}{\text{PR}}=\frac{\text{sin}(15)}{\text{12}}[/tex]
[tex]\frac{\text{sin}(120)}{\text{PR}}=\frac{\text{sin}(15)}{\text{12}}[/tex]
PR = [tex]\frac{12\text{sin}(120)}{\text{sin}(15)}[/tex]
PR = 40.15 km
Therefore, distance between P and R is 40.15 km.
