There are 6 triangles
There are 8 triangles inside a 10 sided decagon
There is 8 triangles in the Star of David.
8
There are 6 triangles in an 8 sided octagon
If it is in the form of two inverted triangles, then there are 8 triangles. If only the outline is used, there are 0 triangles.
A ten-sided geometric figure could have ten triangles drawn inside it, if you connect the vertexes. 8 triangles
By looking at other polygons with less sides, we can see how many triangles they can fit. In a 4-sided polygon (square), you can fit 2 triangles. In a 5-sided polygon (pentagon), you can fit 3 triangles. In a 6-sided polygon (hexagon), you can fit 4 triangles. In an 8-sided polygon (octagon), you can fit 6 triangles. The pattern here is the number of triangles is equal to the number of sides minus 2. T = N - 2 So... 50 - 2 = 48. 48 triangles can fit into a 50-sided polygon.
Because all other polygons are made from triangles as for example an 8 sided octagon has 6 triangles within it or a 6 sided hexagon has 4 triangles within it.
Triangles are needed to form polygons of 3 sides or more as for instance a 6 sided hexagon needs 4 triangles and a 10 sided decagon needs 8 triangles.
tetrakaidecahedron
8 triangles will fit inside a 10 sided decagon