the distance between any 2 points (x1,y1) and (x2,y2) is
[tex]D= \sqrt{(x2-x1)^2+(y2-y1)^2} [/tex]
given
(0,a) and (a,0)
[tex]D= \sqrt{(a-0)^2+(0-a)^2} [/tex]
[tex]D= \sqrt{(a)^2+(-a)^2} [/tex]
[tex]D= \sqrt{a^2+a^2} [/tex]
[tex]D= \sqrt{2a^2} [/tex]
[tex]D= a\sqrt{2} [/tex]
the disance is a√2
