Length of diagonal from bottom to top

[zak100]

1. Homework Statement

I have to find the length of a diagonal from bottom to top. I don't know which formula i would be using? Please see the attachment for more information.

Homework Equations

May be pythagorous theorem. But i don't know which sides i have to select

The Attempt at a Solution

Sorry i need some hint.
Zulfi.

 

[Nidum]

Add one more line to the sketch and the way to solve this problem should become easier for you to see . The added line goes from point A to the point vertically below point B .

 

[SammyS]

View attachment 207943 1. Homework Statement

I have to find the length of a diagonal from bottom to top. I don't know which formula i would be using? Please see the attachment for more information.

Homework Equations

May be pythagorous theorem. But i don't know which sides i have to select

The Attempt at a Solution

Sorry i need some hint.
Zulfi.

To add to @Nidum 's comment:

The added line goes from point A to the corner of the box vertically below point B .

 

[Mark44]

May be pythagorous theorem. But i don't know which sides i have to select

You'll need to use Pythagoras theorem twice.

 

[Kaura]

Try thinking of the line drawn as the vector <10, 7, 2>

 

[zak100]

Hi,
Thanks everybody. Post# 3 provided a clue but i came to know about this when i solved the problem. The other clue is the application of pythagorus theorem on rectangular solids which i got from the following link: https://www.google.com.pk/imgres?im...ved=0ahUKEwiA__Hz3LjVAhVHBcAKHQACAMEQ9QEIJzAA

Let K be the point below B & C is connected to both A & K
AK^2 = AC^2 + CK^2
AB^2 = AK^2 + BK^2
AB^2 = AC^2 + CK^2 + BK^2 = 100 + 49 + 4 therefore AB = 3sqrt(17).

Thanks.

Zulfi.