a = 6 cm b = 8 cm h1 - wysokość Δ równobocznego o bokach długości a = 6 cm h1 = [a√3]/2 = [ 6 cm *√3]/2 = 3√3 cm x = (2/3) h1 = (2/3)*3√3 cm = 2√3 cm h - wysokość ostrosłupa prawidłowego h² + x² = b² h² = b² - x² = 8² - (2√3)² = 64 - 12 = 52 = 4 *13 h = √52 = 2√13 h = 2√13 cm h2 - wysokość ściany bocznej czyli trójkąta równoramiennego (h2)² = b² - (a/2)² = 8² - 3² = 64 - 9 = 55 h2 = √55 h2 = √55 cm Pc = Pp + Pb = [a²√3]/4 = 3*(1/2)*a*h2 = = [ 6²√3]/4 + (3/2)*6*√55 = 9√3 + 9√55 = 9*(√3 + √55) Pc = 9*(√3 + √55) cm² ---------------------------------------- V = (1/3)*Pp *h = (1/3)*9√3 cm² *2√13 cm = 6√39 cm³ =====================================================
Dane: a=6cm b=8cm h1=6 cm ------>[a√3]------>[ 6 cm *√3] h1=-->____--->=_________________--->= 3√3 cm ------->2---------> 2 x = (2/3) h1 = (2/3)*3√3 cm = 2√3 cm h² + x² = b² h² = b² - x² = 8² - (2√3)² = 64 64- 12 = 52 = 4 *13 4 *13 h = √52 √52 = 2√13 h = 2√13 cm (h2)² = b² - (a/2)² = 8² - 3² = 64 - 9 = 55 h2 = √55 h2 = √55 cm Pc = Pp + Pb [a²√3]/4 = 3*(1/2)*a*h2=[ 6²√3]/4 + (3/2)*6*√55 = 9√3 + 9√55 = 9*(√3 + √55) Pc = 9*(√3 + √55)cm² V = (1/3)*Pp *h = (1/3)*9√3 cm² *2√13 cm = 6√39 cm³