Question

Question in attachment.

Answer 1

Please type in the question directly as much as possible, as it allows search through brainly and google.

There are two cases possible. When angle AOB + angle BOC is more than 180° and when it is less than 180°.

See both cases and their solutions.
Proved. Done.

Answer 2

Heya User,

--> I'm Lazy to add pics so, guess, you better do some homework ^_^

=_+ Now, 

-->∠AEC = 180° - ∠EAC - ∠ECA
=> 2∠AEC = 360° - 2∠EAC - 2∠ECA
=> 2∠AEC = 360° - 2∠BAC - 2∠DCA

However, we know that the angle made by a chord on the center is double of that made at the circumference ...

=> 2∠AEC = 360° - ∠BOC - ∠AOD
=> 2∠AEC = ∠BOD + ∠AOC --> [ ∠AOC > 180° is the major angle ]

However, when ∠AOC < 180° , ∠BOD takes its place :) ..

And Hence, we are done ..