posted by cody .
what is the area of a regular quadrilateral (square) that has a radius of 10 square root of 2. The 10 square root of 2 is the x^2 (the hypotenuse) part of a 45-45-90.
What do you mean by the radius of a square? Are you referring to the inscribed circle or the circumscribed (outside) circle?
If 10 sqrt2 is the radius of a circumscribed circle, then the square inside the circle has side lengths of 20. The area is then 400.
it is only a square, no circle. the radius i am refering to is from the corner point to the midpoint of the square. and from the midpoint there is a line going straight down, thus forth a 45-45-90. it is like dividing a sqaure into 4 equal sections, each corner is in 1/4 of the square. then take one section, and cut that straight in half from the midpoint to the corner. that line is the 10 sqrt of 2.
In that case it is like the radius of a circumscribed circle, and the answer I gave is the correct one.