parallelogram and a triangle have the same base and height. The area of the parallelogram is 40 square centimeters. What is the area of the triangle in square centimeters?
一个平行四边形和一个三角形等底等高，平行四边形的面积是40平方厘米，这个三角形的面积是多少平方厘米．
<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<result>20</result>