The apex angle of an isosceles triangle is 70 degrees, how many degrees are each base angle?
一等腰三角形的顶角是70度，每个底角是多少度．
<gadget id="calculator">180 - 70</gadget>
<output>110</output>

<gadget id="calculator">110 / 2</gadget>
<output>55</output>

<result>55</result>