Is AB perpendicular to BC where A =(2,0,-1), B=(4,3,-6) and C = (9,3,-4)

AB = B - A = (4,3,-6)- (2,0,-1) = (2 , 3 , -5)BC = C - B = (9,3,-4) - (4,3,-6) = (5, 0 , 2)
If perpendicular "AB dot BC" should equal zeroAB dot BC = (2,3,-5) dot (5,0,2) = (2x5) + (3x0) + (-5x2) = 10 + 0 +(-10) = 0Therefore AB is perpendicular to BC