Either
12,14,16,or18
I think 18.
* * * * *
The correct answers is 4. You can draw only 3 diagonals from one vertex.
4 are formed
From each vertex to its opposite vertex. These will be centered on a shared point at the center of the hexagon. Each complete line will be a line of symmetry for the hexagon.
13 The correct answer is 12. From any one vertex, you can draw a diagonal to all but 3 vertices: the vertex itself and the next vertex on either side of your vertex (these would be sides of your shape, not diagonals).
n-3 diagonals. Of the n vertices of the polygon, you cannot draw diagonals to the two adjacent vertices since these are sides of the polygon and so not diagonals. And you cannot draw a diagonal from a vertex to itself. So those are three vertices that are ruled out, leaving n-3.
Draw lines from point to point and now you have six triangles to calculate
4.
fourteen. If you draw if diagonals from one vertex there are 14. fourteen. If you draw if diagonals from one vertex there are 14.
four (4)
18
The answer would be 18.
33 triangles
It is: 8-2 = 6 triangles
Five of them
4 are formed
You can draw 9 diagonals inside a hexagon.
Look at it the other way. Draw a hexagon, and draw two horizontal lines, in each case from one vertex to another one. That way you'll see how to divide the hexagon into a rectangle (not necessarily a square), and two triangles - which, of course, you can combine again to form the hexagon.
A 35-gon has 560 diagonals 0.5*(352-3*35) = 560