The base area of the second rectangular prism is 51 cm²
The rectangular prism completely filled with sand has a base area of 85cm² and height of 15cm .
where
B = base area
h = height
Since the first rectangular prism was completely filled with sand and it completely filled the second rectangular prism, it means they both have the same volume.
Therefore,
volume of the first rectangular prism = volume of the second rectangular prism.
Therefore, the base area of the second rectangular prism can be calculated as follows:
volume = Bh
1275 = 25B
B = 1275 / 25
B = 51 cm²
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