At 9 o'clock in the morning or 3 o'clock in the afternoon, what is the angle formed by the hour and minute hands on the clock face?
上午9时或下午3时整，钟面上时针和分针所组成的角是多少度的角．
<gadget id="calculator">30 * 3</gadget>
<output>90</output>

<result>90</result>