In an isosceles triangle, the apex angle is three times the base angle, what is the apex angle in degrees?
一个等腰三角形，它的顶角是一个底角的3倍，顶角是多少度．
<gadget id="calculator">2 + 3</gadget>
<output>5</output>

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

<gadget id="calculator">36 * 3</gadget>
<output>108</output>

<result>108</result>