Explicație pas cu pas:
1.
a): ?=[180-(37+45)]:2=98:2=49
b) ?=[180-(20+78)]:2=82:2=41
c) COD=35*2=70, COB=180-70=110, ?=110:2=55
d) COD=2*30=60, BOE=180-60-89=31, ?=31:2=15.2
e) AOD=23*2=46, EOB=42*2=84, deci:
COD=23, EOF=42, DOE=180-(46+84)=50
f) COD=19, DOE=31, FOB=180-(38+62)=80
FOD=GOB=80:2=40
g) COD=43, DOB=180-86=94, EOF=FOB=94:2=47
h) AOC=36, DOE=EOF=FOB=(180-72):3=108:3=36
2.
a) 3x+x=180, 4x=180, x=180:4=45; AOC=3*45=135, COB=45
b) x+x+100=180, 2x=180-100=80, x=80:2=40; AOC=40, AOB=100+40=180
