If the length of the diagonal of a cube is 43 cm.,then let us calculate the total surface area of the cube.
Let the edge of a cube be a cm.
We know that the body diagonal of a cube = 3a cm
∴ According to question,
3 a = 43
a = 
= 4 cm
As, total surface area of a cube = 6a2 sq.cm
= 6×(4)2
= 6×16
= 96 sq. cm
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