The ratio of the apex angle to the base angle of an isosceles triangle is 2:1, what is the base angle in degrees?
一个等腰三角形的顶角和一个底角度数的比是2：1，它的一个底角是多少度．
<gadget id="calculator">2 + 1 + 1</gadget>
<output>4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">180 * (1/4)</gadget>
<output>45</output>

<result>45</result>