Answer:
828
Step-by-step explanation:
d/6=138
d =138*6
d =828
S1 = 294 square mm
7 * 7 = 49
49 mm per side on the large cube
a cube has 6 faces, or sides
so
49 * 6 =<u> 294 mm</u>
Answer is in the file below
tinyurl.com/wtjfavyw
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