The angle of elevation of the top of an unfinished tower at a point distant 120 m from its base is 45°. If the elevation of the top at the same point is to be 60°, the tower must be raised to a height :

• 120 ( √3 + 1 ) m
• 120 ( √3 - 1 ) m
• 10 ( √3 + 1 )
• None of these