A parallelogram and a triangle have the same area, the base of the parallelogram is 1/4 of the base of the triangle, and the height of the triangle is equal to the height of the parallelogram.
平行四边形和三角形面积相等，平行四边形的底是三角形底的(1/4)，三角形的高是平行四边形高的多少．
<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<gadget id="calculator">2 / 4 / 4 / 1</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">4 * (1/8)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>