A hexagon with two reflex angles opposite one another will have two diagonals that lie entirely outside the hexagon and one that is partly outside.
The figure is a rectangle.
A plane figure is one that is entirely in one plane. One way to think of that is it can be made to lie flat - no ups or downs. A closed figure is one where you can go around the outside of the figure and return to your starting point - without jumping. If you take any two points - one inside the figure and one outside, then you cannot draw a curve from one to the other without crossing the boundary of the figure.
In most shapes the diagonals do not bisect one another. It might be possible to answer the question if it were more specific. To start with, shapes with how many sides?
you can make 2 trapezoids
A hexagon with two reflex angles opposite one another will have two diagonals that lie entirely outside the hexagon and one that is partly outside.
There are 19
The figure is a rectangle.
If you mean "How many diagonals can be drawn from one vertex of a figure with 16 sides", the formula is n-3, where "n" being the number of sides of the figure. So 16-3 = 13 diagonals that can be drawn from one vertex.
The number of diagonals in an equilateral figure can be calculated from the number of sides. If the number of sides is "S", then the number of diagonals would be S(S-3)/2 This becomes clear if you consider that there will be the same number of vertices as there are sides. From each vertex you can draw a diagonal to all vertices except the one you started from and the two adjacent ones (lines between the adjacent vertices and the starting point are sides of the figure, not diagonals). This gives you S·(S-3) but that would double count the diagonals since each diagonal can start at either vertex.
A plane figure is one that is entirely in one plane. One way to think of that is it can be made to lie flat - no ups or downs. A closed figure is one where you can go around the outside of the figure and return to your starting point - without jumping. If you take any two points - one inside the figure and one outside, then you cannot draw a curve from one to the other without crossing the boundary of the figure.
There are no diagonals in any triangle. This is because any line connecting two of the vertices would actually be one of the sides. A diagonal has to run through the middle of the figure...well, not the exact center but you know what I mean :)
A concave Hexagon is that hexagon which has one of its internal angle greater than 180 degrees. It can have 8 diagonals. As compared to regular hexagon (Also convex hexagon) it has one less number of diagonals. This is because one line joining two of its vertices (that are at the end of sides forming >180 angle) fall outside the hexagon.
There are 5 diagonals
The diagonals of a rhombus are lines drawn from one corner, or vertex, to the opposite one. They have two important properties. 1. Diagonals bisects a pair of opposite angles. 2. Diagonals are !!perpendicular!!
You need more information: the length of a side. Then, since the diagonals bisect one another at right angles, you can use Pythagoras's theorem to calculate their lengths.
In most shapes the diagonals do not bisect one another. It might be possible to answer the question if it were more specific. To start with, shapes with how many sides?