Question

plz plz solve it fast..........its really urgent....

Answer 1

to prove : BOC= 180-angle A
Proof: In triangle BCE
 B+BCE+CEB=180
B+BCE+90=180
BCE= BCO =180-(B+90)
=180-B-90............1 
similarly in triangle BCD
 DBC=OBC =180-(C+90)
=180-C-90............2
and in triangle ABC
B=180-(A+C)
=180-A-C...........3
now in triangle BOC 
BOC + OBC+ BCO =180
BOC=180-(OBC+BCO)
BOC=180-(180-C-90+180-B-90) from 1 and 2
=180-(360-180-C-B)
=180-(180-C-(180-A-C))
=180-(180-C-180+A+C)
=180-180+180-A+C-C
BOC=180-A proved