The perimeter of the rectangle is 48 cm, and the ratio of length to width is 5:3. What is the area of the rectangle?
长方形的周长是48厘米，长与宽的比是5：3，长方形的面积是多少？
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">48 / 2 / 8</gadget>
<output>3</output>

<gadget id="calculator">3 * 5 * 3 * 3</gadget>
<output>135</output>

<result>135</result>