tin box is 30 cm long, 15 cm wide, and 15 cm high. What is the minimum square centimeter needed to make such a tin box? (overlap is ignored)
一个铁皮盒长30厘米，宽15厘米，高15厘米．做这样一个铁皮盒至少要用多少平方厘米？(重叠处忽略不计)
<gadget id="calculator">30 * 15</gadget>
<output>450</output>

<gadget id="calculator">15 * 15</gadget>
<output>225</output>

<gadget id="calculator">450 + 450 + 225</gadget>
<output>1_125</output>

<gadget id="calculator">1_125 * 2</gadget>
<output>2_250</output>

<result>2_250</result>