Question

Ajutor va rog frumos,pina marti imi trebuie dau si coroana.

Answer 1

$\it \Delta VOB-dr\ m(\hat O)=90^o\ \stackrel{T.P.}{\Longrightarrow}\ VO^2=VB^2-OB^2\ \Rightarrow\\ \\ \ \Rightarrow\ VO^2=13^2-5^2=169-25=144=12^2\ \Rightarrow\ h=VO=12\ cm$

$\it \mathcal{A}_{\ell}=\pi R G=\pi\cdot5\cdot13=65\pi\ cm^2\\ \\ \mathcal{A}_b =\pi R^2=\pi\cdot5^2=25\pi\ cm^2\\ \\ \mathcal{A}_t= \mathcal{A}_\ell+ \mathcal{A}_b=65\pi+25\pi=90\pi\ cm^2\\ \\ \mathcal{V}=\dfrac{ \mathcal{A}_b \cdot h}{3}=\dfrac{\ 25\pi\cdot12^{(3}}{3}=25\pi\cdot4=100\pi\ cm^3$