Assignment:
A plane flying a straight course observes a mountain at a bearing of 35.3° to the right of its course. At that time the plane is 9 km from the mountain. A short time later, the bearing to the mountain becomes 45.3°. How far is the plane from the mountain when the second bearing is taken (to the nearest tenth of a km)?
Provide complete and step by step solution for the question and show calculations and use formulas.