The top angle of a red scarf is 130°, what is the bottom angle of it?
一条红领巾的顶角是130°，它的一个底角是多少度．
<gadget id="calculator">180 - 130</gadget>
<output>50</output>

<gadget id="calculator">50 / 2</gadget>
<output>25</output>

<result>25</result>