Răspuns:
1.S=(n-2)180°
a)4×180=720°
b)8×180=1440°
c)13×180=2340°
d)18×180=3240°
2.N=(n-2)180/n
a)4×180/6=720/6=120°
b)8×180/10=1440/10=144°
c)13×180/15=2340/15=156°
d)18×180/20=3240/20=162
3.
N=(1-2/n)×180
N/180-1=-2/n
2/n=1-N/180
n=2/(1-N/180)
3.a)n=2/(1-108/180)=>n=5
b)n=2/(1-120/180)=> n=6
c)n=2/(1-150/180)=> n=12
d)n=2/(1-172/180)=> n=45
4. a) 6 un cerc cu raza faci semne
pe circumferința rezultă 6 laturi
b)12 raza /2 => 12 laturi
c)24 r/4 =>24 laturi
