Is there anyway to do this? (connecting radar chart)

If you know the location of the dots (you can get this from any GuiObject with the AbsolutePosition property), then you can use this:

local function DistanceBetweenPoints(PointA, PointB)
    return math.sqrt( math.pow(PointB.X-PointA.X, 2) + math.pow(PointB.Y-PointA.Y, 2) )
end

local function AverageBetweenPoints(PointA, PointB)
    return (PointA.X + PointB.X) * 0.5, (PointA.Y + PointB.Y) * 0.5
end

local function SlopeBetweenPoints(PointA, PointB)
    return (PointB.Y - PointA.Y) / (PointB.X - PointA.X)
end

local function AngleBetweenPoints(PointA, PointB)
    return -math.atan( 1 / SlopeBetweenPoints(PointA, PointB) )
end

local function CreateLineBetweenPoints(PointA, PointB, Thickness, ExtraProps)
    local LineLength = DistanceBetweenPoints(PointA, PointB)
    local LineCenterX, LineCenterY = AverageBetweenPoints(PointA, PointB)
    local LinePositionX = LineCenterX
    local LinePositionY = LineCenterY - math.abs((PointA.Y-PointB.Y) * 0.5)
    local LineAngle = AngleBetweenPoints(PointA, PointB)
    
    local Line = Instance.new("Frame")
    Line.Size = UDim2.new(0, Thickness, 0, LineLength)
    Line.Position = UDim2.new(0, LinePositionX , 0, LinePositionY)
    Line.Rotation = math.deg(LineAngle)
    for Property, Value in pairs(ExtraProps) do
        Line[Property] = Value
    end
    return Line
end

-- Creates a vertical line
local MyLineThickness = 2
local MyLineExtraProperties = 
{
    Name = "MyLine",
    BorderSizePixel = 0,
    BackgroundColor3 = Color3.new(1, 0, 0)
}
local DotAPoint = Vector2.new(100, -50)
local DotBPoint = Vector2.new(100, 20)
local MyLine = CreateLineBetweenPoints(
    DotAPoint, DotBPoint, MyLineThickness, MyLineExtraProperties)
MyLine.Parent = game.Players.LocalPlayer.PlayerGui.ScreenGui