Let a = (8, 3, 5) and b = (8, -10, -5) be vectors. Find the scalar, vector, and orthogonal projections of b onto a .

I was able to easily find the scalar and vector projection, but I need help on orthogonal projection. All I know is that the dot production must equal 0.

Scalar projection = $\displaystyle 9/sqrt(98)$

Vector projection = ( $\displaystyle 36/49$ , $\displaystyle 27/98$ , $\displaystyle 45/98$ )

-Thanks