Question

5- Um cubo tem 5√12 cm de aresta. A medida da sua diagonal é:

a) 5√3 cm
b) 5³√12 cm
c) 30 cm
d) 18 cm

Answer 1

$\large\boxed{\begin{array}{l}\rm \ell=5\sqrt{12}=5\cdot2\sqrt{3}=10\sqrt{3}\,cm\\\rm D=\ell\sqrt{3}\\\rm D=10\sqrt{3}\cdot\sqrt{3}\\\rm D=10\sqrt{3^2}\\\rm D=10\cdot3\\\rm D=30\,cm\\\huge\boxed{\boxed{\boxed{\boxed{\rm\dagger\red{\maltese}~\blue{alternativa~c}}}}}\end{array}}$