If the base and height of a triangle are doubled, what is its original area?
一个三角形的底和高都缩小2倍，它的面积是原来的多少．
<gadget id="calculator">2 / 1</gadget>
<output>2</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

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

<result>1/4 = around 0.25</result>