Can anyone confirm this answer for me?
In a rectangular prism, each face (base & lateral side) is a rectangle. In the given diagram, the lengths of the edge are a, b, and c. Find d.

http://i1005.photobucket.com/albums/af176/xSHiRLEYNATORSx/Capture.jpg?t=1370752005

My answer was d = √(c^2 + y^2)
Is that right? I did this problem relatively faster than I thought so I have precarious feelings about it. Dx

Question

Can anyone confirm this answer for me? 
In a rectangular prism, each face (base & lateral side) is a rectangle. In the given diagram, the lengths of the edge are a, b, and c. Find d.

http://i1005.photobucket.com/albums/af176/xSHiRLEYNATORSx/Capture.jpg?t=1370752005

My answer was d = √(c^2 + y^2) 
Is that right? I did this problem relatively faster than I thought so I have precarious feelings about it. Dx

jim_thompson5910 · Answer

how would you write y^2 in terms of a and b?

anonymous · Answer

ohh y^2 = a^2 + b^2 ?

jim_thompson5910 · Answer

so

$$\large d = \sqrt{a^2 + b^2 + c^2}$$

anonymous · Answer

ohhhhhh xD thanks!!

jim_thompson5910 · Answer

this is the 3D version of the pythagorean theorem

jim_thompson5910 · Answer

yw