If the height of a triangle increases by 25%, how much should the base decrease if the area of the triangle remains the same?
一个三角形的高如果增加25%，要是三角形的面积不变，底应该减少多少
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>