A trapezoidal cotton field measures 16 meters at the top, 23 meters at the bottom, and 28 meters high. If 9 cotton plants are planted per square meter, how many cotton plants can be planted in this field?
一块梯形棉花地，量得上底16米，下底23米，高28米．如果每平方米种棉花9棵，这块地一共可以种多少棵棉花？
<gadget id="calculator">16 + 23</gadget>
<output>39</output>

<gadget id="calculator">28 / 2</gadget>
<output>14</output>

<gadget id="calculator">39 * 14 * 9</gadget>
<output>4_914</output>

<result>4_914</result>