Module code did not return exactly one value?

I'm new to scripting, nothing big. I'm basically trying to make this module work but it continues to return with the same error:   14:19:00.830 Module code did not return exactly one value  -  Studio

I'm just attempting to follow a tutorial, it does mess up a bit and breaks itself but I manage to find the problem and fix it myself. Modules is a whole new area for me and I'm just completely braindead at this point.

Currently I'm insure on how to fix this issue, so here's the current code.

local Triangle do
	local v3 = Vector3.new
	local cf = CFrame.new
	local abs = math.abs
	local cross = v3().Cross
	local dot = v3().Dot
	local clone = game.Clone

	local ref = Instance.new('WedgePart') do
		ref.Color         = Color3.fromRGB(200, 200, 200)
		ref.Material      = Enum.Material.SmoothPlastic
		ref.Reflectance   = 0
		ref.Transparency  = 0
		ref.Name          = ""
		ref.Anchored      = true
		ref.CanCollide    = false
		ref.CFrame        = cf()
		ref.Size          = v3(0.25, 0.25, 0.25)
		ref.BottomSurface = Enum.SurfaceType.Smooth
		ref.TopSurface    = Enum.SurfaceType.Smooth
	end

	local function fromAxes(p, x, y, z)
		return cf(
			p.x, p.y, p.z,
			x.x, y.x, z.x,
			x.y, y.y, z.y,
			x.z, y.z, z.z
		)
	end

	function Triangle(a, b, c, parent, wb, wc, N)
		local ab, ac, bc = b - a, c - a, c - b
		local abl, acl, bcl = ab.magnitude, ac.magnitude, bc.magnitude
		if abl > bcl and abl > acl then
			c, a = a, c
		elseif acl > bcl and acl > abl then
			a, b = b, a
		end
		ab, ac, bc = b - a, c - a, c - b
		local out = cross(ac, ab).unit
		wb = wb or clone(ref)
		wc = wc or clone(ref)
		local biDir = cross(bc, out).unit
		local biLen = abs(dot(ab, biDir))
		local norm = bc.magnitude
		wb.Size = v3(0, abs(dot(ab, bc))/norm, biLen)
		wc.Size = v3(0, biLen, abs(dot(ac, bc))/norm)
		bc = -bc.unit
		wb.CFrame = fromAxes((a + b)/2, -out, bc, -biDir)
		wc.CFrame = fromAxes((a + c)/2, -out, biDir, bc)
		local G = Instance.new("Model", parent)
		G.Name = "Floor" .. N
		wb.Parent = G
		wc.Parent = G
		return wb, wc
	end
end