Question

Draw line l. Take any point P on the line. Using a set square, draw a line perpendicular to line l at the point P.

Answer 1

Steps of construction:
1. Draw line l. Take point P anywhere on the line.
2. Place the set square on the line in such a way that the vertex of its right angle is at point P and one arm of the right angle falls on the line l.
3. Draw a line PQ along the other arm of the right angle of the set square.
4. The line PQ is perpendicular to the line l at P.