Question 86363

           
       R(3,2)=(X1,Y1);S(-1,6)=(X2,Y2); T(-5,-6)=(X3,Y3)
     use distance formula to find RS,ST,&TR
     RS squared =  (X2-x1)squared+(Y2-Y1)squared= (-4)squared+(4)squared=16+16=32
     ST squared=(X3-X2)squared+(Y3-Y2)squared= (-4)squared+(-12)squared=16+144=160
     TR squared=(X3-X1)squared+(Y3-Y1)squared= (-8)squared+(-8)squared=64+64=128
     from the above we can conclude that RS squared+TR squared = ST squared
      therefore RST is a right triangle.