A triangular vegetable field is 30 meters long and 18 meters high. If every kilogram of fertilizer can be applied to 3 square meters of land, how many kilograms of fertilizer should be prepared to fertilize this vegetable field?
一块三角形菜地底长30米，高18米，如果每千克肥料可施3平方米地，给这块菜地施肥，需准备肥料多少千克？
<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">30 * 9</gadget>
<output>270</output>

<gadget id="calculator">270 / 3</gadget>
<output>90</output>

<result>90</result>