A base angle of an isosceles triangle is 50 degrees, and the number of base angles is equal to the number of top angles.
一个等腰三角形一个底角是50度，底角度数是顶角度数的多少．
<gadget id="calculator">180 - 50 - 50</gadget>
<output>80</output>

<gadget id="calculator">50 / 80</gadget>
<output>5/8 = around 0.625</output>

<result>5/8 = around 0.625</result>