Horizontal range is given by, Â
R is maximum if  is maximum.
i.e. Â Â Â
       Â
       Â
Horizontal range is maximum when angle of projection is 45°.Â
Here,
Time taken for the shot to reach the ground, t = 2s.
Velocity in horizontal direction, u = 60 ft/s
The height of the tower = distance fallen by shot in 2sÂ
That is,Â
Â
The distance from the foot of the tower where it strikes the ground, s= ut = 60 x 2 = 120 feet.Â
Horizontal range is given by,
         Â
where,  is the angle of projection and is less thanÂ
We know,Â
      Â
            [Where ]
Now, Â
      and Â
Since   Â
∴      Â
Thus horizontal range is the same for angle of projection θ and α = 90°–θ.Â