Theo đề bài : A^=B^+10*
B^=C^+10*
C^=D^+10*
<=> A^- 10* =C^ +10*
B^- 10* = D^ + 10*
Mà A^+B^+C^+D^=360*
=> A^ - 10*+C^ +10* <=> B^ (+10*-10*)+D^+10*+10*
=>2(A^-10*+C^+10*)=360*
=>A^-10*+C^+10*=180*
Ta có : A^-10*=C^+10* =>A^=C^+10*+10*
=> A^=(180*+10*+10*):2=100*
=>C^=180*-100*=80*
=>B^=80*+10*=90*
=>D^=360*-100*-90*-80*=90*
Vậy ....