Missile trajectory, 16th-century illustration. The angle of firing of this cannon-fired projectile is 45 degrees, resulting in the maximum range. The path of the projectile is shown according to Aristotelian physics. Since Aristotle believed that no body could undertake more than one motion at a time, the path had to consist of two separate motions in a straight line. The actual trajectory is a parabola. Artwork from 'Problematum astronomicorum et geometricorum' (Basel, 1561) by Dutch mathematician and astronomer Daniel Santbech.