Question

Calcule o número de diagonais: D=N(n-3) A)N=10 B)N=8 C)N=7 D)N=6 E)N=12

Answer 1

RESOLVENDO :
==============
Vamos calcular com a seguonte formula :
D = n ( n - 3 )
......._______
...............2


A) N = 10
....._____
D = n (n - 3)
.......______
..............2

D = 10 (10 - 3)
.......________
.................2

D = 10 (7)
......._____
............2

D = 70
.......___
.........2

D = 35

B) N = 8
...._____
D = n ( n - 3 )
......._______
...............2

D = 8 (8-3)
......._____
.............2

D = 8 (5)
......._____
............2

D = 40
........___
...........2

D = 20

C.-) N = 7
.......____
D = n ( n - 3 )
........_______
................2

D = 7 (7-3)
......._____
............2

D = 7 (4)
......._____
...........2

D = 28
.......____
..........2

D = 14

D.-) N = 6
......._____
D = n ( n - 1 )
......._______
..............2

D = 6 (6-3)
......._____
.............2

D = 6 (3)
.......____
...........2

D = 18
........___
...........2

D = 9

E.-) N = 12
......._____
D = n ( n - 3 )
......._______
................2

D = 12 ( 12 - 3 )
.......________
.................2

D = 12 (9)
........_____
............2

D = 108
........____
............2

D = 54