One base angle of an isosceles triangle is 62 degrees, find the apex angle of this isosceles triangle.
等腰三角形的一个底角是62度，求这个等腰三角形的顶角．
<gadget id="calculator">62 * 2</gadget>
<output>124</output>

<gadget id="calculator">180 - 124</gadget>
<output>56</output>

<result>56</result>