You actually wants to calculate the volume in cubic meters.

Volume for this solid, a cobblestone rectangle, is calculated simply multiplying area of the base by its height.

Replacing the given values in the formula, we get

V = A_{B}h = 90 x 405 x 5 cm^{3}

V = 182250 cm^{3}

Now we convert to cubic meters by dividing by 100x100x100 = 100,000.

V = 182250/100,000 = 1.8225 m^{3} (cubic meters) (answer)

so, you will need approximately 2 m^{3} of sand cement mix.

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