If the ratio of an angle to its supplementary angle is 1:4, what is the angle in degrees?
一个角与它的补角之比为1：4，则这个角等于多少度．
<gadget id="calculator">1 + 4</gadget>
<output>5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">180 * (1/5)</gadget>
<output>36</output>

<result>36</result>