Cylinder
because you can't just change one of the angles or one of the side lengths without breaking the triangle. All the angles and sides re-inforce each other. Image a square made out of sticks that are attached loosely at the corners. You can squish two of the corners together to make a diamond shape, and you haven't changed the length of the sides. But if you have a triangle made out of sticks, you can't change it's shape without destroying it.
The most rigid shape that you can make out of straight pieces is the triangle.
triangle , square , rectangle
No. Hexagons and squares will each tessellate by themselves but one can not make a tessellation out of hexagons and squares combined. However, if you add in a third shape, the triangle, one can make a tessellation.
There is no shape that is made up 3 sides that is not a triangle. Any shape that is made up of 3 sides is classified as a triangle no matter what shape or size it is.
A metal triangle is a percussion instrument consisting of a metal rod bent into a triangle shape, and a pot is a container typically made of ceramic or metal used for cooking or storing food. Combining the two would result in a metal triangle suspended above a pot, with the potential for creating musical sounds by striking the triangle.
A square, a cube, a diamond, a equilateral triangle, a triangular based pyramid made of equilateral triangles...
A triangle is the most stable shape out of the three because it has three sides that distribute forces evenly. A square is next in terms of stability because it has four equal sides, while a diamond is the least stable due to its slanted sides that can cause it to tip over more easily.
It will be a polygon, although the exact nature of the resulting polygon will depend on the original polygon, its dimensions relative to the triangle, whether or not the two shapes can overlap and so on.
A right angle triangle or an isosceles triangle.
Cylinder
because you can't just change one of the angles or one of the side lengths without breaking the triangle. All the angles and sides re-inforce each other. Image a square made out of sticks that are attached loosely at the corners. You can squish two of the corners together to make a diamond shape, and you haven't changed the length of the sides. But if you have a triangle made out of sticks, you can't change it's shape without destroying it.
The triangle is a percussion instrument and is in the shape of a triangle and is made from metal- this instrument is normally played with a beater to make diferent sounds which start and finish before the next sound is made. :)
a square
The most rigid shape that you can make out of straight pieces is the triangle.
triangle , square , rectangle