Question

Which of the following is an example of right angle?

1. Angle between the sides of your pentagonal room floor.

2. The angle between the sides of a set square.

3. Angle included between the hour hand and minute hand when it is $12:15$ in your wall clock.

• A. 1
• B. 2
• C. 2 & 3
• D. 1 & 3

Answer 1

The correct option is B

2

The angle between the sides of a pentagonal floor can never be 90 degrees. The two set squares that you have are both right angled triangles. So, one of the angles is ${90}^{\circ }$. When it is $12:15$, the angle included between the hour hand and the minute hand is not ${90}^{\circ }$, it is slightly lesser than that because the hour hand moves in clockwise direction too as the minute hand moves.