In this question without doing a lot of calculation how can we quickly identify that ABC and BDC are equilateral triangles? I could do it only after assuming radius and applying 30-60-90 rule but in the video Greg quickly identified that these would be equilateral triangles I didn’t understand how did he arrive at this so quickly (ofc he is Greg) but still is there some rule or property that I am missing out?
Like, I drew a perpendicular from both the vertex C and B over the line AD and using algebra found out that AB is equal to AC and same for BD and CD. So, it did take around 6-7 minutes to do this
