a) BOC=COE
BOC=COD+DOE
BOC=X+X+70=2X+70
BOC=70⁰
AOB+BOC+COD+DOE+EOA=360⁰
90+2X+70+X+70+X+2X+40=360
270+6X=360
6X=360-270
6X=90
X=90/6
X=15⁰
BOC=2C+70=1·15+70=100
BOC=100⁰
COD=X+70=15+70=85
COD=85⁰
DOE=X
DOE=15⁰
EOA=2X+40=2·15+40=70
EOA=70⁰
b·) EOM·=MOA
EOM=EOA/2=70/2=35
EOM=35⁰
MOD=DOE·+EOM
MOD=15+35=50
MOD=50⁰
NOC=BON
NOC=BOC/2=100/2=50
NOC=50⁰
MOD=NOC=50⁰