Simple harmonic motion is shown to be the projection on a diameter of which motion?

1. A rotating point and an oscillating one turn out to be related. 2. Dropping a perpendicular from the circle gives the oscillation. 3. The projection of uniform circular motion on a diameter of the circle follows simple harmonic motion. 4. So the answer is uniform circular motion. _Source: syllabus Physics Part II, Ch 13 'Oscillations'_