a)
A/3=B/4=C/8=D/9=k
A/3=k=>A=3k
B/4=k=>B=4k
C/8=k=>C/8k
D/9=k=>D=9k
A+B+C+D=360°
3k+4k+8k+9k=360°
24k=360°=>k=15°
A=3k=3•15°=45°
B=4k=4•15°=60°
C=8k=8•15°=120°
D=9k=9•15°=135°
b)
A=0,5B=0,(3)C=0,25D=k
A=k
0,5B=k<=>B/2=k=>B=2k
0,(3)C=k<=>C/3=k=>C=3k
0,25D=k<=>D/4=k=>D=4k
A+B+C+D=360°
k+2k+3k+4k=360°<=>10k=360°=>k=36°
A=k=36°
B=2k=2•36°=72°
C=3k=3•36°=108°
D=4k=4•36°=144°
