In this program, we use the formulae **v sin A - (1/2)gt ^{2} **
as the vertical component of the displacement and

**v cos A**as the horizontal component of the displacement( where

**g**is the gravitational acceleration ,

**v**the launch velocity and

**A**the launch angle). To enable the missile to fly, we used a combination of the

**Object.Move**method and the object coordinate system , i.e.

**object. left**and

**object.Top**.

We also use the randomize method so that the objects will appear at different positions randomly at each new game. In addition, we use the randomize method to load different backgrounds at start up and at each new game.