square
If you have 2 EQUILATERAL triangles, and you stack them on their respective hypotenuses, the result: SQUARE. If you have 2 ISOSCELES triangles, and you stack them on their respective hypotenuses, the result: RECTANGLE. If you have 2 OBTUSE triangles, and you stack them on their respective hypotenuses, the result: PARALLELOGRAM.
Any two triangles which are a mirror image of each other will form a kite if their long sides are brought together.
Oh, dude, an octahedron is made up of 8 triangles. Yeah, like, imagine a stop sign, but in 3D and with triangles instead of sides. So, if you're ever in a geometry showdown and someone asks you how many triangles are in an octahedron, you can confidently say 8 and totally impress them.
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 square, a cube, a diamond, a equilateral triangle, a triangular based pyramid made of equilateral triangles...
A Rhombus. If it makes two equilateral triangles with a diagonal, the shape must have all four sides of equal length; thus it is a rhombus, possibly a square. As an equilateral triangle is made, the angle between two of the sides is 60o; which is not 90o, so it can't be a square, so it must be a rhombus.
square
It would depend on the triangles, but assuming they were equilateral or isosceles, a trapezoid if alternated in a line.
The Great Pyramids at Giza are, but the Meso-Americans were truncated.
A heptagon is a shape with 7 sides. A regular heptagon is the normal version you will see however an irregular heptagon is any shape with 7 sides.To see it visually, use the triangles to create a normal hexagon (6 sides), remove one of the triangles and put it next to one of the edges near the gap.If done correctly this will create a 7 sided object - an irregular heptagon.
It is a tetrahedron
Rohmbus is a four sided figure (quadrilateral) that is made up of two equilateral triangles
If you have 2 EQUILATERAL triangles, and you stack them on their respective hypotenuses, the result: SQUARE. If you have 2 ISOSCELES triangles, and you stack them on their respective hypotenuses, the result: RECTANGLE. If you have 2 OBTUSE triangles, and you stack them on their respective hypotenuses, the result: PARALLELOGRAM.
Depending on their shapes and sizes you can make plane shapes with 3 to 24 sides.
It doesn't exist. The least number of sides for a 3-D shape only made of triangles is 4.
There are an infinite number of options. Even sticking with polygons with sides of the same measure, a hexagon can be made from 6 equilateral triangles, or 4 eq triangles and a 60 degree rhombus, or 2 eq triangles and 2 60-deg rhombi, or 3 60-deg rhombi. Each of the equilateral triangle could be made from smaller shapes. Eg four equilateral mini-triangles to make 1 triangle. Or 2 mini-triangles and 1 mini-rhombus or 2 60-deg mini-rhombi. And then each of those mini triangles could be made up of smaller micro-shapes. And so on ...