In order to protect the trees, a layer of lime needs to be applied to the trunk of the big tree. The measured circumference of the trunk cross section is 12.5 decimeters, and the height of the plaster is 12 decimeters, so how many square meters is the area of this big tree covered with lime?
为了保护树木，需要在大树的树干上涂一层石灰．量得树干横截面的周长是12.5分米，所涂石灰的高度是12分米，那么这棵大树所涂石灰的面积是多少平方米？
<gadget id="calculator">12.5 * 12</gadget>
<output>150</output>

<result>150</result>