Mathematics

Problem

At a point

A

on level ground the angle of elevation of the top of a tower is

45^{\circ}

. After walking

30\,\text{m}

straight towards the tower to point

B

, the angle becomes

60^{\circ}

. Calculate the height of the tower (nearest tenth). a)

41.0\,\text{m}

71.0\,\text{m}

50.0\,\text{m}

81.0\,\text{m}