Parallelogram diagonal calculation

arkelon19

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Apr 6, 2020
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Hey everyone, I need some help with question c of that exercise.The answer to that question is 2√29 but I can't figure out why. I'm obviously missing something, are there some kind of rules with parallelograms diagonals I forgot ?
A detailed explanation would be very much appreciated, thanks a lot!
Screenshot 2020-04-06 at 17.54.28.png
 
You need to show what work you've been able to do. If we know that we can help you better.

Here's a start for a). Notice that triangles ABC and CDB have both the same height and base. Thus they have the same area. What are the height and base for these triangles?

-Dan
 
I calculated the perimeter of ABCD by using the Pythagora theorem to find CD. And for (a) I just multiplied 12 by 4.
The answer to (a) is 48 and the answer to be is 24+4√5
 
I calculated the perimeter of ABCD by using the Pythagora theorem to find CD. And for (a) I just multiplied 12 by 4.
The answer to (a) is 48 and the answer to be is 24+4√5
It sounds like you got a) right (it is 48) but I don't know if you are saying you got b) right?

The following diagram will help you with c).

-DanParallelogram.png
 
Just drop your perpendicular from B and calculate the diagonal.
 
I would draw the perpendicular to BC from D. Then invoking Pythagorus:

BD2 = (12-2)2 + 42
 
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