`u = , v = ` Find the angle theta between the vectors.

You need to use the formula of dot product to find the angle between two vectors, `u = u_x*i + u_y*j, v = v_x*i + v_y*j` , such that:

`u*v = |u|*|v|*cos(theta)`

The angle between the vectors u and v is theta.

`cos theta = (u*v)/(|u|*|v|)`

First, you need to evaluate the product of the vectors u and v, such that:

`u*v = u_x*v_x + u_y*v_y`

`u*v = 1*0 + 0*(-2)`

`u*v = 0`

Hence, since `u*v = 0` , it does not matter what are the values of the magnitudes |u| and |v| since `cos theta = 0` .

`cos theta = 0 => theta = pi/2`

Hence, the angle between the vectors u and v is `pi/2` , so, the vector u is perpendicular to the vector v.