2023 SJI P1 Q2

The following diagram shows a tower situated along the same line as points A and B on level ground.

Diagram not drawn to scale.

The distance from point A on level ground to the top of the tower is 70 metres. At point B which is 30 metres closer to the tower on level ground, the distance to the top of the tower reduces to 50 metres.

1. Find the angle of elevation from point B to the top of the tower.[3]
2. Hence find the height \(h\) of the tower.[2]