Question

calcule a área de um círculo cujo diâmetro mede 18 cm?​

Answer 1

$\sf A=\pi\cdot\left(\sf\dfrac{d}{2}\right)^2$

$\sf A=3{,}14\cdot\left(\sf\dfrac{18}{2}\right)^2$

$\sf A=3{,}14\cdot9^2$

$\sf A=3{,}14\cdot81$

$\boxed{\boxed{\sf A=254{,}34\,cm^2}}$