The ratio of the apex angle to the base angle of an isosceles triangle is 1:2, what is the apex angle of the triangle?
等腰三角形顶角与底角的比是1：2，那么三角形的顶角是多少°．
<gadget id="calculator">2 / 1 / 2 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<result>36</result>