The angle of elevation of the unfinished tower is 45° from a point 45 m away from the base of the tower. After the tower is finished, the angle of elevation of the top of the tower from the same point becomes 60°. Find the height of the newly built part (√3 = 1.732).
1
33 m
2
37.5 m
3
78 m
4
22.5 m