∵EF⊥AB
∴∠AOF=90
∴∠COF=∠AOF-∠AOC=90-∠AOC
∵OG平分∠COF
∴∠COG=1/2∠COF=1/2(90-∠AOC)=45-1/2∠AOC
∴∠DOG=180-∠COG=180-(45-1/2∠AOC)=135+1/2∠AOC
∵OH平分∠DOG
∴∠DOH=1/2∠DOG=1/2(135+1/2∠AOC)=135/2+1/4∠AOC
∵∠AOC:∠DOH=8:29
∴∠DOH=29/8∠AOC
∴135/2+1/4∠AOC=29/8∠AOC
∴∠AOC=20
∴∠DOH=29/8∠AOC=145/2=72.5
∴∠COH=180-∠DOH=180-72.5=107.5