Question

va rog frumos ajută-mă la subpunctul b​

Answer 1

$\it \mathcal{P}_b=3\cdot\ell=3\cdot2\sqrt3=6\sqrt3\ cm\\ \\ \\\mathcal{A}_b=\dfrac{\ell^2\sqrt3}{4}=\dfrac{(2\sqrt3)^2\sqrt3}{4}=\dfrac{4\cdot3\sqrt3}{4}=3\sqrt3\ cm^2\\ \\ \\ \mathcal{A}_\ell=3\cdot\ell\cdot h=3\cdot2\sqrt3\cdot7=42\sqrt3\ cm^2\\ \\ \\ \mathcal{A}_t=\mathcal{A}_{\ell}+2\cdot\mathcal{A}_b=42\sqrt3+6\sqrt3=48\sqrt3\ cm^2\\ \\ \\ \mathcal{V}=\mathcal{A}_b \cdot h=3\sqrt3\cdot7=21\sqrt3\ cm^3$