Question

a) R =6 cm e r = 2,5 cm
b) R = 15 cm e r = 5 cm
c) R = 9,5 cm e r = 2,5 cm
d) R = 12 cm e r = 8 cm​

Answer 1

Resposta:

Explicação passo-a-passo:

Área da coroa Circular=$Ac=\pi (R^2-r^2)$

A) R=6cm  e r=2,5cm

$Ac=\pi (6^2-2,5^2)\\Ac=3(36-6,25)\\Ac=3.29,75\\Ac=89,25cm^2$

B)R=15cm e r=5cm

$Ac=3(15^2-5^2)\\Ac=3(225-25)\\Ac=200.3=600cm^2$

C)9,5cm e 2,5cm

$Ac=3(9,5^2-2,5^2)\\Ac=3(90,25-6,25)\\Ac=3.84\\Ac=252cm^2$

D)R=12cm e r=8cm

$Ac=3(12^2-8^2)\\Ac=3(144-64)\\Ac=3.80\\Ac=240cm^2$