Trees are planted on the four sides of a square land, and all four vertices are planted, and there are 20 trees on each side, and the distance between the trees is 5 meters. What is the side length of this square?
在一块正方形地的四条边上种树，四个顶点上都种，且每边上有20棵树，树与树之间的距离为5米．这块正方形地的边长是多少米？
<gadget id="calculator">20 - 1</gadget>
<output>19</output>

<gadget id="calculator">5 * 19</gadget>
<output>95</output>

<result>95</result>