The perimeter of an isosceles triangle is 20 decimeters, the length of its base is (1/5) of the perimeter, what is the length of one of its sides in decimeters.
一个等腰三角形的周长是20分米，它的底边长是周长的(1/5)，它的一条腰长是多少分米．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">20 * (1/5)</gadget>
<output>4</output>

<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<result>8</result>