Question

Aria laterala a unui cilindru circular drept este egala cu jumatate din aria sa totala. Comparati raza si inaltimea sa. Multumesc anticipat!

Answer 1

$\mathcal{A}_l=\dfrac{\mathcal{A}_t}{2} \Longrightarrow \mathcal{A}_t =2 \mathcal{A}_l$

[tex]\mathcal{A}_t =\mathcal{A}_l + 2\mathcal{A}_b \ \ \ \ (2) \\\;\\ (1), (2) \Longrightarrow 2\mathcal{A}_l =\mathcal{A}_l + 2\mathcal{A}_b\Longrightarrow \mathcal{A}_l = 2\mathcal{A}_b [/tex]

$2\pi RG = 2\pi R^2 \Longrightarrow G = R.$