The perimeter of an isosceles triangle is 43 cm, the base is 19 cm, what is its waist?
一个等腰三角形的周长是43厘米，底是19厘米，它的腰是多少．
<gadget id="calculator">43 - 19</gadget>
<output>24</output>

<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<result>12</result>