Pc i V kfiatek: Oblicz Pc i V : a) graniastosłupa prostego sześciokątnego o krawędzi podstawy 5. b) walca, którego przekrojem osiowym jest prostokąt o bokach 4 i 6 .

Janek 191: a) a = r = 5 Brak wysokości graniastosłupa − h Wzory: Pc = 2 Pp + Pb = 2 * 6 *a² √3/4 + 6 a*h = 3 a² √3 + 6a*h ====================================================== V = Pp *h = 1,5 a² √3 * h ========================= b) Walec 1 przypadek: 2 r = 4 => r = 2 h = 6 Pc = 2 Pp + Pb = 2 * π *r² + 2 π *r *h Pc = 2 π *2² + 2 π*2*6 = 8 π + 24 π = 32 π j² −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− V = Pp*h = π r² * h = π * 2² * 6 = 24 π j³ −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 2 przypadek: 2r = 6 => r = 3 h = 4 Pc = 2 Pp + Pb = 2 π r² + 2 π r*h Pc = 2 π *3² + 2 π*3*4 = 18 π + 24 π = 42 π j² −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− V = Pp*h = π r² * h = π *3² * 4 = 36 π j³ −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−