The base of a triangle is 12 cm and the height is 8 cm. If the height of the triangle is reduced by 20%, how much should the base be increased to keep the area of the triangle constant?
一个三角形的底是12厘米，高8厘米，如果这个三角形的高减少20%，要使这个三角形的面积不变，底应增加多少．
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">12 * 4</gadget>
<output>48</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">8 * (4/5)</gadget>
<output>32/5 = around 6.4</output>

<gadget id="calculator">2 / (32/5)</gadget>
<output>5/16 = around 0.3125</output>

<gadget id="calculator">48 * (5/16)</gadget>
<output>15</output>

<gadget id="calculator">15 - 12</gadget>
<output>3</output>

<gadget id="calculator">3 / 12</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>