There is an isosceles triangle whose perimeter is 27 meters. It is known that the ratio of the two sides of this triangle is 1:3. Then, what is the base of this isosceles triangle.
有一个等腰三角形的周长是27米，已知这个三角形的两条边的比是1：3，那么，这个等腰三角形的底是多少．
<gadget id="calculator">1 + 3 + 3</gadget>
<output>7</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">27 * (1/7)</gadget>
<output>27/7 = around 3.857143</output>

<result>27/7 = around 3.857143</result>