Make a cuboid with a length of 5 cm, a width and a height of 4 cm with a wooden board, and paint a layer of paint on the surface of the cuboid wood block. What is the area painted in square centimeters?
用木板做一个长5厘米，宽和高都是4厘米的长方体，在长方体木块的表面涂一层油漆，涂油漆的面积是多少平方厘米．
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">20 + 20 + 16</gadget>
<output>56</output>

<gadget id="calculator">56 * 2</gadget>
<output>112</output>

<result>112</result>