Question

Fie un trunchi de con circular drept . Dacă R= 12 , r= 7 , h= 5 . Calculați volumul trunchiului de con

Answer 1

   
[tex]\displaystyle\\ V = \frac{\pi h}{3} (R^2 + r^2 + Rr)=\\\\ =\frac{5\pi }{3} (12^2 + 7^2 + 12\times 7)=\\\\ =\frac{5\pi }{3}(144 + 49 + 84) =\\\\ =\frac{5\pi }{3} \times 277= \frac{5 \times 277 \times\pi }{3}= \boxed{ \frac{1385\pi }{3} ~cm^3} \sim \boxed{1450,095~cm^3}[/tex]