If the base of a triangle is 6 cm and the height is 3 cm, what is the area of a parallelogram with the same base and height in square centimeters?
一个三角形的底是6厘米，高是3厘米，与它等底等高的平行四边形的面积是多少平方厘米．
<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<result>18</result>