Question

calcule a área de um círculo de 25 cm de diametro

Answer 1

$\Large\displaystyle\text{ \begin{gathered} \sf{ A=\pi\cdot\bigg(\dfrac{d}{2}\bigg)^2} \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{ A=3{,}14\cdot\bigg(\dfrac{25}{2}\bigg)^2} \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{ A=3{,}14\cdot12{,}5^2} \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{A=3{,}14\cdot156{,}25 } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \boxed{\boxed{\sf{A=490{,}625\,cm^2}} } \end{gathered} }$