The base of a parallelogram is 7dm, the height is 3dm, what is the area of the triangle with the same base and height as d㎡.
一个平行四边形的底是7dm，高是3dm，和它等底等高的三角形的面积是多少d㎡．
<gadget id="calculator">7 * 3</gadget>
<output>21</output>

<gadget id="calculator">21 / 2</gadget>
<output>21/2 = around 10.5</output>

<result>21/2 = around 10.5</result>