A cuboid has a square base, its base perimeter is 20 cm, and its height is 15 cm. What is the surface area of this cuboid in square centimeters?
一个长方体，底面是正方形，它的底面周长是20厘米，高是15厘米，求这个长方体的表面积是多少平方厘米？
<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">5 * 15</gadget>
<output>75</output>

<gadget id="calculator">25 + 75 + 75</gadget>
<output>175</output>

<gadget id="calculator">175 * 2</gadget>
<output>350</output>

<result>350</result>