How would you find the angle two parts hit each other?

I want to apply a velocity based on where a player touches another player or part.

Let's say I touch PlayerB and I am facing left <--- on a 2D plane. I want to apply a velocity to the left with the X-axis. Vice versa on the right.

However, I also want to be able to apply a downward or upward velocity if I touch the player or the part from above (straight down) or upwards when the hand touches the part/player via animation on all situations.

Current code is

local function getAngle(vectorA, vectorB)
    return math.acos(vectorA.Unit:Dot(vectorB.Unit))
end

local vectorA = player.Character[part].CFrame.lookVector
local vectorB = otherPart.CFrame.lookVector
local angle = getAngle(Vector2.new(vectorA.X, vectorA.Y), Vector2.new(vectorB.X, vectorB.Y))

The angle is always positive. When I get the x and y components, they're also always positive.

local verticalAngle = math.deg(math.sin(angle))
local verticalVelocity = initialVelocity * verticalAngle

The initialVelocity will always be positive as it's just a calculation of how much velocity is needed. The angle should determine whether it's upwards or downwards.

Issue in Studio: When touching in a direction, the target part moves to the right (positive direction) at all times. If you hit in the right, the y will also go up. However, if you hit in the left, the y will be down while the part continues to go right on the x-axis.

My goal: A way to ensure that if I touch the part from above (EG animation of touching it from above), the part goes down. If I touch it on my left, the part goes left and maybe up if I touch it at that angle or down if I touch it to the left but downwards. Etc.