Try it on paper first. A hint, the key idea and the worked solution are here when you need them.
Two points lie on opposite sides of a tower, on a line through its foot, m apart. From one point the angle of elevation of the top is , and from the other it is . Find the height of the tower and the larger of the two distances from the foot.
Two observation points on a line through the foot of a tower give two right triangles. On the same side, and , so . On opposite sides the distances add: . The nearer point sees the larger angle.
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. The distances. The point with is from the foot. The point with is from the foot.
Step 2. They add to m. , so .
Step 3. The height. m.
Step 4. The larger distance. m.
Check. m.
Answer: the tower is m tall, and the larger distance is m.
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