A parallelogram has the same area and height as a triangle. If the base of the parallelogram is 20 cm, what is the base of the triangle?
一个平行四边形与一个三角形面积相等，高也相等．如果平行四边形的底是20厘米，则三角形的底应该是多少厘米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 20</gadget>
<output>10</output>

<result>10</result>