The base of a parallelogram is 18 cm long and the height is 1/2 of the base. What is its area?
一个平行四边形的底长18厘米，高是底的(1/2)，它的面积是多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">18 * (1/2) * 18</gadget>
<output>162</output>

<result>162</result>