2008 UNCO Math Contest II Problems/Problem 3
Problem
A rectangle is inscribed in a square
creating four isosceles right triangles.
If the total area of these four triangles
is 
, what is the length of the diagonal
of the rectangle?
![[asy] draw((0,0)--(1,0)--(1,1)--(0,1)--cycle,black); draw((0,2/3)--(2/3,0)--(1,1/3)--(1/3,1)--cycle,black); [/asy]](http://latex.artofproblemsolving.com/3/3/e/33e59fc38b33e85160f8d9df01198f561a06c879.png)
Solution
Without loss of generality, squeeze the rectangle into a line that becomes the diagonal of the square. 2 of the triangles approach 0 area as the rectangle approaches a line and the diagonal of the rectangle approaches the line, so we can treat this as a question of "What is the length of the diagonal of a square of area 200?"
We see that the side of the square must be 
, and because the hypotenuse of the 45-45-90 triangle formed by the diagonal is 
*side length, we see that the diagonal of the square and therefore the diagonal of the rectangle is 
or 
.
See Also
| 2008 UNCO Math Contest II (Problems • Answer Key • Resources) | ||
| Preceded by Problem 2 |
Followed by Problem 4 | |
| 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 | ||
| All UNCO Math Contest Problems and Solutions | ||
