projn(PR)
- The idea is very similar to finding that for the line with a few differences.
- To do projections, we need a receiving vector, we used d in lines, here we’ll use n.
- In lines we have a direction vector representing the direction of the line.
- In planes we have a normal vector perpendicular to the plane.
- Since n is perpendicular to the plane, the projection of PR onto n will give us the shortest distance itself.
- The perp will give us the distance from P to Q (the shortest distance-walla point).
- This is opposite to that of the plane where the perp gives the distance and proj gives the point.