Question

in a ABC AB = 40
BAC = 20
BD ls angle bisector of ABC
o is circumcenter
Find ADO​

Answer 1

Given that in ΔABCΔABC , ∠BAC=85∘∠BAC=85∘ & ∠BCA=75∘∠BCA=75∘

∴∠ABC=180∘−∠BAC−∠BCA∴∠ABC=180∘−∠BAC−∠BCA

=180∘−85∘−75∘=180∘−85∘−75∘

=20∘=20∘

Now, by property of chord of circle that the angle subtended by any chord at the center of circle is equal to double the angle subtended by the same chord at any point in the corresponding segment of circle,

∴∠AOC=2∠ABC=2(20∘)=40∘∴∠AOC=2∠ABC=2(20∘)=40∘

Now, in isosceles ΔAOCΔAOC , ∠OAC=∠OCA∠OAC=∠OCA

∴∠AOC+∠OAC+∠OCA=180∘∴∠AOC+∠OAC+∠OCA=180∘

40∘+2∠OAC=180

Answer 2

Answer:

$\huge\underline\bold\red{Answer}$⬆️⬆️

$<b><marquee>$I Hope it helps uh.....