<PRE><B>Question 254125</B>
Hello, 
We can use the following formula to solve this. A^2 + B^2 = c^2 
A and B will be the sides of the rectangle. Plug in the numbers.
12^2 + 5^2= C^2 This can be rewritten as:
144+ 25 = C^2  
169 = C^2 Square root both sides will give us:
C = 13 
There we go the length of the diagonal is is 13 feet long. 
RJ
Check out a new math book at 
www.math.unlock.com
</PRE>