What is the volume of a cuboid whose base is a square with a circumference of 20 cm and a height of 7 cm?
一个长方体，底面是周长20厘米的正方形，高7厘米，它的体积是多少．
<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">5 * 5 * 7</gadget>
<output>175</output>

<result>175</result>