For triangles and parallelograms of equal area, if the base of the triangle is three times the base of the parallelogram, then its height is equal to the height of the parallelogram.
面积相等的三角形和平行四边形，如果三角形的底是平行四边形底的3倍，那么它的高是平行四边形高的多少．
<gadget id="calculator">2 / 1 / 3</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>