If the area of a parallelogram is 30 square decimeters, what is the area of a triangle with the same base and height?
一个平行四边形的面积是30平方分米，与它等底等高的三角形的面积是多少平方分米
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">30 * (1/2)</gadget>
<output>15</output>

<result>15</result>