Look at the answer here: http://web2.0calc.com/questions/una-pir-mide-quadrangular-recta-d-aresta-10-mm-i-altura-5-mm and use the same method.
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Look at the answer here: http://web2.0calc.com/questions/una-pir-mide-quadrangular-recta-d-aresta-10-mm-i-altura-5-mm and use the same method.
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