Dad bought Xiaoli an isosceles triangle kite. One of its base angles is 75 degrees, what is its top angle?
爸爸给小丽买了一个等腰三角形的风筝．它的一个底角是75度，它的顶角是多少度？
<gadget id="calculator">75 * 2</gadget>
<output>150</output>

<gadget id="calculator">180 - 150</gadget>
<output>30</output>

<result>30</result>