In an isosceles triangle, the degree of a base angle is (1/4) of a top angle, how many degrees is a base angle.
一个等腰三角形中，一个底角的度数是一个顶角的(1/4)，一个底角是多少度．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4) + (1/4)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">180 / (3/2)</gadget>
<output>120</output>

<gadget id="calculator">120 * (1/4)</gadget>
<output>30</output>

<result>30</result>