A(n)=4+4(n-1)
a(n)=4+4n-4
a(n)=4n
76=4n
n=19
The sum of any arithmetic sequence (series are infinite) is:
(a+a(n))(n/2)
The average of the first and last terms times the number of terms, in this case we found that n=19 so:
19(4+76)/2=760
Area de la base es un hexagono: Nota: asumiendo que 39 cm son el lado de un hexagono. Menuda pizza.
A = 3*sqrt(3)/2*a^2 = 3*sqrt(3)/2*39^2 = 3951.67391746839972 cm^2
Hay dos base y tapa, doble:
7903.34783493679944 cm^2
Luego los lados verticales:
6 * 39 * 4.7 = 1099.8 cm^2
TOtal = 9003.14783 = 9003.147 cm^2 = 9003.15 cm^2