Question

A área de uma tela retangular é 200cm². Sabendo que a largura é 1/2 da altura, quais são as dimensões desta tela

Answer 1

$\boxed{\begin{array}{l}\underline{\rm \acute Area~do~ret\hat angulo}\\\sf A= \ell\cdot h\\\sf \ell\longrightarrow largura\\\sf h\longrightarrow altura\\\tt dados\begin{cases}\sf \ell=\dfrac{1}{2} h\implies h=2\ell \\\sf \ell=?\\\sf h=?\end{cases}\\\underline{\boldsymbol{Soluc_{\!\!,}\tilde ao}}\\\sf A=\ell \cdot h\\\sf A=\ell\cdot2\ell\\\sf 2\ell^2=A\\\sf 2\ell^2=200\\\sf\ell^2=\dfrac{200}{2}\\\\\sf \ell^2=100\\\sf \ell=\sqrt{100}\\\sf \ell=10~cm\\\sf h=2\cdot10=20~cm\end{array}}$