Why doesnt my script work?:Tryingtocallmethodonobjectoftype:`Vector3`withincorrectarguments

So i am making an myth game and i need to use this script:

function onTouched(part)
if part.Parent ~= nil then
local h = part.Parent:findFirstChild("Humanoid")
if h~=nil then			
h.Parent.HumanoidRootPart.Velocity=Vector3.new(x,y,z)
Sound:Play()
script.Parent.Parent.HalfSphere.Size = Vector3.new()(2.9, 0.7, 2.9)
wait(0.5)
script.Parent.Parent.HalfSphere.Size = Vector3.new()(3.9, 1.7, 3.9)				
end
end
end

When i click "play" it says Trying to call method on object of type: Vector3 with incorrect arguments. (in line 12) Can you help with this?