7
10 triangles
if you need to know how many triangles are in a polygon ... just take the number of its sides and subtract for example. nonagon has 9 sides so it will be 9-2=7 so, a nonagon has 7 triangles
Nine, as a n-gon can be cut in n-2 triangles.
4 triangles make 1 hexagon. (easy way to find out how many triangles there are in a polygon- take number of sides of the polygon, subtract 2 from it, that's your answer!)
Yes, you can but it take 3 triangles.
4, one for each side face
It needs only 2 triangles to construct a parallelogram
A minimum of 2 triangles are needed, but you can also make a rectangle with 3 or more triangles.
2 triangles make up a rhombus which has 4 interior angles adding to 360 degrees and a triangles has 3 interior angles add up to 180 degrees. Therefore: 360/180 = 2 triangles
it depends on what you mean by a diagonal. If you take a diagonal to mean a line from one corner to the "opposite" corner, then a nonagon doesn't have any, and a decagon has five. The reason a nonagon doesn't have any, is that the corners aren't opposite each other.
take three match for each triangle
to make a model of a food pyramid take a cardboard and cut it in 3 triangles and then make a triangle shape with those triangles,then go to the web and search pic of foodpyramid