Question

Find the number of right angles turned through by the hour hand of a clock when it goes from:
3 to 6

Answer 1

A complete revolution of the hour hand covers 12 hours or four right angles i.e ${360}^{\circ }$. Which means 1 hour = ${30}^{\circ }$.
When the hour hand goes from 3 to 6, the time difference = 6 - 3 = 3 hours i.e one-fourth of 12 hours.
$\Rightarrow$ $\frac{1}{4}$th of ${360}^{\circ }$
$\Rightarrow$ ${90}^{\circ }$
= One right angle.