If the base angle of an isosceles triangle is twice the apex angle, what is the apex angle of the triangle?
一个等腰三角形的底角是顶角的2倍，这个三角形的顶角是多少°．
<gadget id="calculator">1 + 2 + 2</gadget>
<output>5</output>

<gadget id="calculator">180 / 5</gadget>
<output>36</output>

<result>36</result>