Răspuns:
Explicație pas cu pas:
L = 16π = 2πR
R = 16π : 2π = 8 cm
A = πR^2 = 64π cm^2
________
L = 6√2π cm
R = 6√2π : 2π = 3√2 cm
A = 18 cm^2
_________
L = 13π cm
R = 13π : 2π = 6,5 cm
A = 42,25 cm^2
_______________________
A = πR^2 = 100π cm^2
R^2 = 100; R = 10 cm
L = 2πR = 20π cm
________
A = 80π cm^2
R^2 = 80; R = 4√5 cm
L = 8√5π cm
________
A = 108π cm^2
R^2 = 108; R = 6√3 cm
L = 12√3π cm