hi...

When the projectile is thrown parallel to the horizontal , the angle of projection is 0°.

One of the key components of projectile motion and the trajectory that it follows is the initial launch angle . This angle can be anywhere from 0 to 90 degrees. The angle at which the object is launched dictates the range, height, and time of flight it will experience while in projectile motion .

Drear aspirant

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Answer is 0°

When the projectile is thrown parallel to the horizontal , the angle of projection is 0°.

If you want know by diagram then it is like

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