The perimeter of an isosceles triangle is 70 cm. If the perimeter remains the same, it becomes a triangle whose waist and base are 2:3, and then a triangle whose waist and base are 3:2. At this time, the waist is longer than the original waist. how many centimeters.
一个等腰三角形周长是70厘米，周长不变把它变成腰和底是2：3的三角形，再变成腰和底是3：2的三角形，这时的腰比原来的腰长多少厘米．
<gadget id="calculator">2 + 3 + 3</gadget>
<output>8</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">2 + 2 + 3</gadget>
<output>7</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(3/8) - (2/7)</gadget>
<output>5/56 = around 0.089286</output>

<gadget id="calculator">70 * (5/56)</gadget>
<output>25/4 = around 6.25</output>

<result>25/4 = around 6.25</result>