It is: 0.5*(10 squared - (3*10)) = 35 diagonals
decagon
35
A decagon has 10 sides and 35 diagonals
A decagon has 35 diagonals. This can be computed by multiplying ten by seven and dividing by two. Seven is derived from the number of sides minus three.
54 Diagonals. * * * * * A polygon with n sides has 1/2*n*(n-3) diagonals. So a decagon would have 1/2*10*7 = 35 diagonals. How the Community answer got 54 is anybody's guess!
There are 35 diagonals in a 10 sided decagon
A tetra-decagon is a 14 sided polygon having 77 diagonals
8
decagon
35.
35
35
A decagon has 10 sides and 35 diagonals
35 diagonals
A decagon has 10 sides. To find the number of pairs of parallel diagonals in a decagon, we need to consider the possible combinations of diagonals that are parallel to each other. Each vertex can connect to 5 other vertices with a diagonal, but not all of these diagonals will be parallel. Therefore, the number of pairs of parallel diagonals in a decagon is 10 choose 2, which equals 45 pairs.
A decagon has 35 diagonals. This can be computed by multiplying ten by seven and dividing by two. Seven is derived from the number of sides minus three.
35 diagonals