hou to prove formula 
 
Diagonal of a cuboid =  l^2+b^2+h^2
 
 

Asked by arunyadav6 | 3rd Oct, 2014, 09:59: PM

Expert Answer:

Let space AB equals straight l comma space BC space equals space straight b comma space CD equals straight h In space increment ABC comma space angle straight B equals 90 degree comma Applying space Pythagoras space theorem space in space increment ABC comma AC equals square root of AB squared plus BC squared end root equals square root of straight l squared plus straight h squared end root In space increment ADC comma space angle straight C equals 90 degree Applying space pythagoras space theorem comma AD equals square root of AC squared plus CD squared end root equals square root of open parentheses square root of straight l squared plus straight h squared end root close parentheses squared plus straight h squared end root equals square root of straight l squared plus straight b squared plus straight h squared end root therefore Diagonal space of space straight a space cuboid space equals square root of straight l squared plus straight b squared plus straight h squared end root

Answered by Prasenjit Paul | 4th Oct, 2014, 11:57: AM

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