Giải
a) Lần lượt tính :
\(\widehat{BOC}=40^0;\widehat{COM}=20^0;\widehat{AOM}=\widehat{AOC}+\widehat{COM}=60^0+20^0=80^0\)
b) Lần lượt tính :
\(\widehat{BOC}=m-n,\widehat{COM}=\frac{m-n}{2}\)
\(\widehat{AOM}=\widehat{AOC}+\widehat{COM}=n+\frac{m-n}{2}=\frac{m+n}{2}\)