There is a big tree on the playground of the Experimental Primary School, and there is a 2.5-meter-high bamboo pole next to it. At 9:00 a.m., the students simultaneously measured the shadow of the bamboo pole to be 2 meters long, and the shadow of the big tree to be 6 meters long. What is the actual height of the big tree? ﹙Using proportional solutions﹚
实验小学操场上有一棵大树，旁边有一根2.5米高的竹竿，上午9时，同学们同时测得竹竿的影长2米，大树的影长6米，大树的实际高是多少？﹙用比例解﹚
<gadget id="calculator">2.5 / 2</gadget>
<output>1.25</output>

<gadget id="calculator">1.25 * 6</gadget>
<output>7.5</output>

<result>7.5</result>