Yes, these are swing low/high. For Dow I also consider US election low as significant point and it gave great angles. Getting right scale to draw angles is challenge and I worked on that for last 2 years. I use 6 scales for weekly angles (so 6 charts). All angles work as support and resistance. But one of the chart works very well for certain swing move and that chart becomes trading chart.
Take case of TCS chart attached. This particular scale captured recent move so well.