[tex]\Large\underline{\rm Solution :- }[/tex]
Theorem : Angle subtended at the centre is double the the angle subtended at the circumference of the circle .
Here [tex]\overline{AOC}[/tex] is a straight line. So it's measure is 180°. Therefore the angle subtended at the circumference will be ,
[tex]\implies \angle ABC = \dfrac{1}{2}\times 180° \\\\\implies \boxed{ \angle ABC = 90° }[/tex]
Remember: Angle in a semicircle is 90°.
