Mom bought an isosceles triangle kite for Dongdong. One of its base angles is 50 degrees. What is its top angle?
妈妈给东东买了一个等腰三角形的风筝，它的一个底角是50度，它的顶角是多少度．
<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<gadget id="calculator">180 - 100</gadget>
<output>80</output>

<result>80</result>