8. An angle can be represented by two capital letters on its two sides and the letter of its vertex, the symbol for $\angle A O B$ (" $\angle$ " represents an angle), and it can also be represented by $\angle O$ (when there is only one angle at the vertex). In the triangle $\mathrm{ABC}$ below, $\angle B A O=\angle C A O, \angle C B O=\angle A B O$, $\angle A C O=\angle B C O, \angle A O C=110^{\circ}$, then $\angle C B O=$
【Answer】 $20^{\circ}$
【Question Type】Geometry: Angle
【Analysis】From the problem, we get $\left\{\begin{array}{l}2(\angle C A O+\angle A C O+\angle C B O)=180^{\circ} \\ \angle C A O+\angle A C O+\angle A O C=180^{\circ} \\ \angle A O C=110^{\circ}\end{array}\right.$, solving this gives $\angle C B O=20^{\circ}$.