A square and a rectangle have the same perimeter. The side length of the square is 7.5 cm. The ratio of the length to width of the rectangle is 2:1. What is the area of the rectangle in square centimeters?
一个正方形和一个长方形的周长相等，正方形的边长是7.5厘米，长方形的长和宽的比是2：1，这个长方形的面积是多少平方厘米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">7.5 * 2</gadget>
<output>15</output>

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">15 * (2/3)</gadget>
<output>10</output>

<gadget id="calculator">15 - 10</gadget>
<output>5</output>

<gadget id="calculator">10 * 5</gadget>
<output>50</output>

<result>50</result>