At 3 o'clock, what is the angle between the hour and minute hands on the clock face?
3时整，钟面上的时针和分针成多少°的角．
<gadget id="calculator">360 / 12</gadget>
<output>30</output>

<gadget id="calculator">30 * 3</gadget>
<output>90</output>

<result>90</result>