Which of the following is an example of perpendicular lines?
1. Corners of your circular room floor
2. One of the angles in both your set squares
3. Angle included between the hour hand and minute hand when it is 12:15 in your wall clock
2
There are no corners in a circular floor! The 2 set squares that you have are both right angled triangles. So, one of the angles is 90∘. When it is 12:15, the angle included between the hour hand and the minute hand is not 90∘, it is slightly lesser than that because the hour hand moves in clockwise direction too as the minute hand moves.