I understand the basic concept of find the area of shaded region then minus the area of the triangle. And to find area of shaded region we need angle BED - which I’m not sure how to find

Consider r = 4. Then by given data, ED = 2 and EB = 4. By Pythagorus you can find BD = 2root(3). which shows the above triangle is 30-60-90

So BED should be 60

1 Like