square
Trusses are structural elements made up of a series of interconnected triangles. This design helps to distribute loads efficiently and increase stability in buildings and bridges.
An hexagon is made up out of 4 triangles
The Great Pyramids at Giza are, but the Meso-Americans were truncated.
Polygons with 11 to 20 sides, known as hendecagons to icosagons, do not inherently contain triangles as part of their structure. However, any polygon can be divided into triangles through triangulation, which involves drawing diagonals. This process can create multiple triangles within the polygon, but the polygon itself is not made up of triangles.
27, but you will have to prove it.
Israel
An object made up of three rectangles and two triangles could be a house. The rectangles can represent the main structure and the door, while the triangles can represent the roof. This simple geometric composition is often used in basic architectural designs or children's drawings of houses.
An octagon is made up from six triangles each containing 180 degrees.
a geometric shape made up of 20 triangles. :)
geodesic
Assuming ALL 22 triangles are congruent, this would be a 22-gon, also known as an icositedigon
It would depend on the triangles, but assuming they were equilateral or isosceles, a trapezoid if alternated in a line.