Xiao Ming's height is 1.4 meters, and the length of his shadow is 2.8 meters. If the shadow length of a tree measured at the same place at the same time is 7 meters, how tall is the tree?
小明的身高是1.4米，他的影子长是2.8米．如果同一时间，同一地点测得一棵树的影子长是7米，这棵树有多高？
<gadget id="calculator">1.4 / 2.8</gadget>
<output>0.5</output>

<gadget id="calculator">0.5 * 7</gadget>
<output>3.5</output>

<result>3.5</result>