dTriangle

local p1,p2,p3 = Workspace['Point1']['Position'], Workspace['Point2']['Position'], Workspace['Point3']['Position'];

function AngleBetween(v1, v2)
    return math['deg'](math['acos']( (v1:Dot(v2))/(v1['magnitude'] * v2['magnitude']) ))
end

function GetWedge()
    local p = Instance['new']([[WedgePart]], Workspace);
    p['TopSurface'], p['BottomSurface'] = "Smooth", "Smooth";
    p['Anchored'] = true;
    p['FormFactor'] = "Custom";
    --p['Size'] = Vector3['new'](.1,5,5);
    return p;
end

function GetPoint()
    local p = Instance['new']("Part", Workspace)
    p.FormFactor = "Symmetric"
    p.BrickColor = BrickColor.Blue()
    p.Size = Vector3.new(1,1,1)
    p.Anchored = true
    return p;
end

function DrawLine(to, from)
    --[[
        Required an object
    local f = Instance.new("FloorWire", Workspace)
    f.To = to;
    f.From = from
    f.Color = BrickColor.Yellow();]]
    local r = Instance.new("Part")
    r.FormFactor = "Custom"
    r.Size = Vector3.new(0, 0, (from-to)['magnitude'])
    r.Anchored = true
    r.BrickColor = BrickColor.Yellow();
    r.CFrame = (CFrame.new(to, from))
    r.CFrame = r.CFrame + (r.CFrame.lookVector * r.Size.Z/2)
    r.Parent = Workspace
end

function dTriangle(v1,v2,v3)
    local A, B, C = AngleBetween((v2-v1)['unit'], (v3-v1)['unit']), AngleBetween((v1-v2)['unit'], (v3-v2)['unit']), AngleBetween((v1-v3)['unit'], (v2-v3)['unit']);
    local a, b, c = (v3-v2)['magnitude'], (v1-v3)['magnitude'], (v1-v2)['magnitude'];
    DrawLine(v1, v2);
    DrawLine(v2, v3);
    DrawLine(v3, v1);
    if A ~= 90 and B ~= 90 and C ~= 90 then -- no right triangle
        local longest;
        if A > B and A > C then
            local adjacent = math['cos'](math.rad(B)) * c
            local bisector = v2 + ((v3-v2)['unit'] * adjacent);
            local bisector_length = math.sqrt(c^2 - adjacent^2)--(bisector-v1)['magnitude']
            local np = GetPoint()
            np.CFrame = CFrame.new(bisector)
            DrawLine(v1, bisector);
            local w1 = GetWedge();
            local tl = (w1.CFrame * CFrame.Angles(math.rad(90),0,0)).lookVector;
            local mid = v1 + ((v2-v1)['unit'] * c/2);
            local nl = CFrame.new(mid, v3).lookVector
            local d = tl:Dot(nl)/(tl.magnitude * nl.magnitude);
            w1.Size = Vector3.new(0,adjacent, bisector_length);
            w1.CFrame = (CFrame.new(mid) * CFrame.Angles(0,0,math.acos(d)))-- * CFrame.Angles(0,0,-math.pi);
        elseif B > A and B > C then
            local adjacent = math['cos'](math.rad(C)) * a
            local bisector = v3 + ((v1-v3)['unit'] * adjacent);
            local np = GetPoint()
            np.CFrame = CFrame.new(bisector)
            DrawLine(v2, bisector);
        else -- C is greatest angle
            local adjacent = math['cos'](math.rad(A)) * b
            local bisector = v1 + ((v2-v1)['unit'] * adjacent);
            local np = GetPoint()
            np.CFrame = CFrame.new(bisector)
            DrawLine(v3, bisector);
        end
    else -- already a right triangle
        local w = GetWedge();
        if A == 90 then -- point1 is the 90
            --w['CFrame'] = CFrame['new'](v1 ) * CFrame['Angles'](0,math['rad'](-90),math['rad'](90));
        elseif B == 90 then

        else

        end
    end
    print(A,B,C)
end

dTriangle(p1,p2,p3);