Math open ended question?pls help..?

Nina has a 9.25 inch square piece of paper. She wants to make a triangle by cutting the corner along the dotted line in the diagram provided in the link below. What should be the value of x so that sides A, B, and C will be equal?





http://i72.photobucket.com/albums/i174/w...

Math open ended question?pls help..?
If you resolve the small triangle and apply Pythagoras theorem, you get:


x^2 + x^2 = B^2





Since C = B = 9.25 -x, substitute the value in the above equation and solve it. i.e,


x^s + x^s = (9.25 - x)^2 or


2 x^2 = (9.25-x)^2.


Take square roots on both sides and simplify to get an answer of 3.831 for x.
Reply:A=9.25-x


B²=X²+X²=2X² (Pythagoras's theorem)


therefore, B=√2X²


C=9.25-x


let A=B=C


i.e. √2X²=9.25-x, then solve for x.


Note, √2=1.414


1.414x=9.25-x


x=9.25/2.41


therefore, x=3.84 (approx)

rose