The perimeter of an isosceles triangle is 35 cm, the ratio of the base to the length of a waist is 3:2, what is the length of the base in cm.
一个等腰三角形周长是35CM，底与一条腰的长度的比是3：2，底边的长度是多少CM．
<gadget id="calculator">3 + 2 + 2</gadget>
<output>7</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">35 * (3/7)</gadget>
<output>15</output>

<result>15</result>