Prove that the quadrilateral with vertices (2,5), (4,8), (7,6) and (5,3) is a rectangle.

step-by-step explanation:

assume that you have 3 different side lengths.   apply the pythagorean theorem here:   square each of the two shortest sides; call them a and b, so that their squares are a² and b².   also square the longest side, calling the result c².

now, if a² + b² = c² is true, the triangle is a right triangle; otherwise it is not a right triangle.

68719476736

step-by-step explanation:

8*8*8*8*8*8*8*8*8*8*8*8=68719476736