A triangle has the same base and the same height as a parallelogram. If the area of the parallelogram is 30 square centimeters larger than that of the triangle, what is the area of the triangle in square centimeters?
一个三角形与一个平行四边形的底相等，高也相等，如果平行四边形的面积比三角形的面积大30平方厘米，那么这个三角形的面积是多少平方厘米．
<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">30 / 1</gadget>
<output>30</output>

<result>30</result>