Question

O diametro de uma circumnferencia medem 4 cm qual o comprimento dessa cirunferencia

Answer 1

c=2piR
R=D/2       ...R= 4/2=2
c=2*3,1415*2
c=12,56 cm

Answer 2

$r= \frac{d}{2}\to r= \frac{4}{2} \to r=2cm\\\\ \\C= 2\pi r \to \\\\C=2*3,14*2\to \\\\C=12,56 cm$