Plant trees on one side of a road. A total of 9 trees are planted from one end of the road to the other. It is known that the distance between every two trees is 20 meters. How many meters is this road?
在一条路的一边种树，从这条路的一端到另一端一共种了9棵树，已知每两棵树之间的距离是20米，这段路有多少米？
<gadget id="calculator">9 - 1</gadget>
<output>8</output>

<gadget id="calculator">20 * 8</gadget>
<output>160</output>

<result>160</result>