Răspuns :
Răspuns:
L=2π·r
L=5·2π=>L=10π=>L≈10·3,14=>L≈31,4 cm
L=7,5·2π=>L=15π cm=>L≈47,1 cm
L=10/π·2π=>L=20cm
[tex]L = 2\pi *r\\\\a)~L=2\pi *5 = 10\pi ~cm\\\\b)~L=2\pi *7,5=15\pi ~cm\\\\c)~L=2\pi *\frac{10}{\pi }=20~cm[/tex]
Răspuns:
L=2π·r
L=5·2π=>L=10π=>L≈10·3,14=>L≈31,4 cm
L=7,5·2π=>L=15π cm=>L≈47,1 cm
L=10/π·2π=>L=20cm
[tex]L = 2\pi *r\\\\a)~L=2\pi *5 = 10\pi ~cm\\\\b)~L=2\pi *7,5=15\pi ~cm\\\\c)~L=2\pi *\frac{10}{\pi }=20~cm[/tex]