Answer
The two vectors are orthogonal. a * b = 0
Work Step by Step
We know two vectors are orthogonal if and only a * b = 0
We know two vectors are perpendicular if the angle between them is (pi/2) or 90 degrees.
a= <9,3> and b =
9*(-2) + 3*6 = 0
Therfore two vectors are othrogonal