Please, help me to solve the problem:
Two fire towers are located 85 km apart on hills A and B. The bearing from A to B is north east. A fire F is observed from tower A at N10E and from B at N75W. The town at point C is on bearing of N25E from A and S70W from B. The observers report the wind is blowing the fire directly toward C at a rate 9km/h. How many hours do the officials have to evacuate the town?
I can't find the distance FC
Sorry, I'm completely stupid , but
how to get the angles <A =20 and <B=25? It can be easily proved that their sum is 45 degrees... Why aren't they 22 and 23 degrees, or 18 and 27, for example?
If I could catch about angles then I can find everything for the problem.
According to your question the line AC and the North direction include an angle of 25°.
Therefore the angle at A is 45° - 25° = 20°
You'll get the interior angle at B in a similar way:
The line BC and South include an angle of 70°.
The line BA and South include anangle of 45°.
etc + andsoon