Consider the following statements about orthogonal projection:

1. The foot of the perpendicular drawn from any point on any line is the orthogonal projection of that point.
2. The orthogonal projection of a line perpendicular to another line is a point of zero length.
3. A line segment parallel to a definite line is equal in length to its orthogonal projection on that line.

• ai and ii
• bi and iii
• cii and iii
• di, ii and iii