How do I make a part the size of a ray?

i have been trying to make my part the size of the ray but i do not know what to put. I would appreciate if someone would help me out.

Here is my code

local RemoteEvent = game.ReplicatedStorage.RemoteEvent
RemoteEvent.OnServerEvent:Connect(function(Player,mouseCframe)
    local Mouse = Player:GetMouse()
    local Origin = script.Parent.Position
    local Direction = (mouseCframe - Origin).Unit
    Direction = Direction * 100
    local ray = Ray.new(Origin,Direction)
    local Parts = workspace:FindPartOnRay(ray,nil)
    print(Parts)
    local Part = Instance.new("Part",game.Workspace)
    Part.Anchored = true
    local length = (Direction - Origin).Magnitude
    Part.Size = Vector3.new(0.5,0.5,length)
    Part.Position = ???
end)