They are called polygons
In general, a parallelogram. But if the triangles are joined along their odd side, a rhombus.
a geometric shape made up of 20 triangles. :)
A triangle that can be made in more than one way
An octagonal pyramid has eight triangles on an octagonal base. An octahedron can also be made by putting a square pyramid on another inverted square pyramid. This shape has just eight triangles and no others.
yes
Yes
Yes
Yes because there are 540 degrees in a pentagon and 180 degrees in a triangle so 540/180 = 3 triangles.
Yes because 3*180 are the interior degrees of a pentagon.
Yes. You can always draw a "diagonal" line between opposite corners of any four-sided figure. Then, cutting along that line, you wind up with two triangles out of which the figure could have been made.
You can always find opposite corners that can be connected with a line which divides the quadrilateral into two trilaterals.
It is a three dimensional figure of some sort.
A 16 sided polygon is made from 14 triangles
Because the sum of the sides of three triangles is nine... Placing three triangles together so they all touch effectively removes four of the total number of sides - leaving five.
A dodecagon is a 12 sided shape made from 10 triangles
Rohmbus is a four sided figure (quadrilateral) that is made up of two equilateral triangles