The mainframe of a certain computer is 60 cm long, 20 cm wide, and 45 cm high. How many square centimeters of dustproof cloth do you need to make a dustproof cover for the mainframe? (bottom and back not done)
某电脑的主机长60厘米，宽20厘米，高45厘米，给主机做一个防尘罩，至少需要多少平方厘米的防尘布？(底面和后面不做)
<gadget id="calculator">60 * 45 * 2</gadget>
<output>5_400</output>

<gadget id="calculator">60 * 20</gadget>
<output>1_200</output>

<gadget id="calculator">20 * 45</gadget>
<output>900</output>

<gadget id="calculator">5_400 + 1_200 + 900</gadget>
<output>7_500</output>

<result>7_500</result>