Find the measure of the angle subtended by $\widehat{ACB}$ in the given figure:

The correct option is C

${280}^{\circ }$

We know that the central angle of a circle is ${360}^{\circ }$

$\widehat{AB}$ subtends $\angle AOB$

$\widehat{ACB}$ subtends the reflex angle $\angle AOB$

$\Rightarrow$ Reflex $\angle AOB=360-$ acute $\angle AOB$

$=360-80={280}^{\circ }$

Hence, measure of $\widehat{ACB}={280}^{\circ }$