A 4-sided polygon has 2 diagonals.
A 5-sided polygon, 5.
6-sided, 9.
By induction, an n-sided polygon has 'n*(n-3)/2' diagonals.
"n" is how many sides a shape has.
so, (7)*(7-3)/2
now we have, 7*4/2
so, 28/2 = 14
Therefore, a 7-sided polygon would have 14 diagonals.
An eight-sided polygon has 8 vertices. Consider1st vertex = 7 diagonals to other vertices2nd vertex = 6 diagonals to other vertices (since one has now been used)3rd vertex = 54th vertex = 45th vertex = 36th vertex = 27th vertex = 18th vertex = 0, so7+6+5+4+3+2+1 = 28Improved Answer:-Formula for finding diagonals of a polygon 0.5*(n2-3n) when n is the number of sides0.5*(82-24) = 20 diagonals
It can have 5 triangles
Providing that it is a regular 7 sided polygon then each interior angle is 900/7 degrees
The number of diagonals in a polygon with n sides is n*(n-3)/2 This is double the number of sides so n*(n-3)/2 = 2*n That is n*(n-3) = 4n Dividing both sides by n gives (n-3) = 4 So that n = 7. A heptagon has 7*4/2 = 14 diagonals.
Not to 1000 degrees but a 7 sided polygon's interior angles add up to 900 degrees
A 7 sided polygon has 14 diagonals
14 diagonals
7-3 = 4
8+7+6+5+4+3+2+1 = 36 diagonals
A polygon with 14 diagonals will have 7 sides
A 7 sided polygon is called a heptagon or a septagon.
7
7
7
An heptagon has 7 sides and 14 diagonals
the polygon has 7 sides, therefore it is a heptagon. =] katrina
The name of a 7 sided polygon is Heptagon.