How many triangles can be formed by joining the vertices of a decagon?

120
The number of triangles created by joining the vertices of a decagon is 120.

How many triangles can be dissected from a decagon?

This eliminates 10(43)=40 triangles.

How many vertices does a triangle of a regular polygon with ten sides?

=8. 10 sides also means 10 vertices. Any three of those vertices define a triangle. So, the number of triangles that can be formed is the same as the combinations of 10 items taken 3 at a time.

How many triangles fit in a Nonagon?

Properties of all nonagons

Number of diagonals	27
Number of triangles	7
Sum of interior angles	1260°

How many sides has a decagon have?

10
Decagon/Number of edges

How many triangles can be formed by joining the vertices of an n sided polygon?

The number of triangles is 1, 8, 35, 110, 287, 632, 1302, 2400, 4257, 6956 for polygons with 3 through 12 sides. If we connect all vertices of a regular N-sided polygon we obtain a figure with = N (N – 1) / 2 lines. For N=8, the figure is: Careful counting shows that there are 632 triangles in this eight sided figure.

How many triangle can be formed by joining the vertices of a octagon?

We have found that the number of triangles that can be formed by joining the vertices of an octagon is 56.

How many diagonals and triangles can be formed by joining the vertices of the polygon having 10 sides?

N	Triangles with 3 diagonal endpoints	Total Number of Triangles
10	120	2400
11	165	4257
12	220	6956
13	286	11297

How many triangles can be formed from a decagon?

In a decagon, by joining one vertex to the remaining vertices you can have 8 triangles. If you are considering all the vertices independently you will have a total of 8*10 = 80 triangles.

How many triangles can be formed from one vertex of a polygon?

In any polygon, if any one vertex is joined with all remaining vertices the number of triangles formed is always 2 less than the number of sides of the polygon…. For n sided polygon, triangles formed= (n-2) But here every vertex( all the vertices) is joined with remaining vertices. Like, in hexagon( 6sided polygon) , vertices are say 1,2,3,4,5,& 6.

How many vertices are there in a hexagon?

There are 6 vertices of a hexagon. One triangle is formed by selecting a group of 3 vertices from given 6 vertices. This can be done in 6C3 ways. = 3!3!6! Was this answer helpful?

How to choose two sides of a triangle with $N-4$?

Also, the two sides that are on the right and left of $AB$ are not to be picked, for else the triangle would share two sides with the polygon. Thus, those are two less points to choose from, and you have $n-4$. Multiply the choices, and you are done.$\\endgroup$