Volume question?

enter image source here

3 Answers
Feb 21, 2018

#12#cm

Explanation:

This is a generalisation of Pythagoras' theorem to #3# dimensions.

The length of the diagonal is:

#sqrt(6^2+5^2+9^2) = sqrt(36+25+81) = sqrt(142) ~~ sqrt(144) = 12#

Feb 21, 2018

The answer is 12 cm.

Explanation:

Firstly, you draw a diagonal line through the base of the rectangular prism. Now you get two triangles and can find the hypotenuse. #6^2 + 5^2 = 61^2#

Now you can make a triangle and imagine that the diagonal line going through the whole prism is the hypotenuse and calculate it with the given height.

#61^2 + 9^2 = 142^2#

If you take the root out of 142 and turn it into decimal, you get 11.916...

Feb 22, 2018

#12##cm#

Explanation:

Similar to the Pythagoras Theorem, the length of the diagonal for a rectangular prism is: #sqrt(l^2+w^2+h^2)#

Therefore, #d=sqrt(6^2+5^2+9^2)#

#=>d=sqrt(36+25+81)#

#=>d=sqrt(142)#

#=>d~~11.92#

#12cm# is the closest

The formula, by the way, can be used to find the diagonal of a similar situation in the 4D. (You just need to add another dimension squared)