If a vertex angle of an isosceles triangle is 55°, what is the base angle?
等腰三角形的一个顶角为55°，则底角为多少度．
<gadget id="calculator">180 - 55</gadget>
<output>125</output>

<gadget id="calculator">125 / 2</gadget>
<output>125/2 = around 62.5</output>

<result>125/2 = around 62.5</result>