In an electric blender, put frozen fresh watermelon cubes, fresh watermelon juice, tequila, fresh squeezed lime juice, triple sec, and 2 cups of ice cubes.
Blend all the ingredients until smooth.
Take two serving glasses and pour the margarita into them.
Garnish each glass with a fresh watermelon triangle and lime wedges.
Enjoy your homemade Cindy McCain Watermelon Margarita!