The ratio of the two acute angles of a right triangle is 3:6, what is the degree of the smaller angle.
直角三角形两个锐角度数的比是3：6，较小角是多少度．
<gadget id="calculator">180 - 90</gadget>
<output>90</output>

<gadget id="calculator">3 + 6</gadget>
<output>9</output>

<gadget id="calculator">3 / 9</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">90 * (1/3)</gadget>
<output>30</output>

<result>30</result>