It is known that Bo and Co are bisectors of ∠ ABC and ∠ ACB of △ ABC respectively, and Bo and co intersect at O. this paper attempts to explore whether there is a fixed quantitative relationship between ∠ BOC and ∠ a

It is known that Bo and Co are bisectors of ∠ ABC and ∠ ACB of △ ABC respectively, and Bo and co intersect at O. this paper attempts to explore whether there is a fixed quantitative relationship between ∠ BOC and ∠ a


(1) Conjecture: ab = AC + CD. Prove: as shown in Figure 2, when AE = AC is intercepted on AB and De is connected, ∵ ad is the angular bisector of ∵ BAC, ∵ ad = ad, ≌ ade ≌ ADC (SAS), ∵ AED = ≌ C, ed = CD,