The base of a parallelogram is 10.5 decimeters and the height is 4 decimeters. What is the area of the triangle with the same base and height?
一个平行四边形的底是10.5分米，高是4分米，与它等底等高的三角形的面积是多少．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

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

<result>21</result>