Proving angles are equal in i triangle in a circle.

[markosheehan]

 

hi can someone help me work this out. i think it has something to do with the exterior angle of a triangle is equal to the sum of the interior angles but i cant work it.

[Sriman Dutta]

Do you know the intersecting chord and tangent properties of circle?

 

Hint : ang. TAB is bisected by AC. And in a circle the angle between the tangent and a chord is equal to the angle at the remaining segment.

[markosheehan]

i know that it means the red angle and the blue angle are the same but i dont know where to go from there