Two regular tetrahedrons connected face to face make a "regular triangular dipyramid." That is one of the 92 "Johnson solids." Those are the convex polyhedrons whose faces are regular polygons but do not belong to either of the two sets of highly symmetric polyhedrons (the Platonic and the Archimedean) or to the perhaps less interesting two infinite families of prisms and antiprisms. If the two tetrahedrons overlap, both centers at the same place but with the tetrahedrons facing in opposite directions, it makes a "stellated octahedron."
Four faces, six edges, and four vertices.... I'm pretty sure... like 92%.
A pyramid will not roll and you cannot stack objects on top.
Yes. You can stack a regular pyramid.
The answer depends on what the stack is made up of.
yes
Tetrahedrons and quadrilaterals.
Tetrahedrons are triangular based pyramids that have 4 faces, 6 edges and 4 vertices which were built by the ancient Egyptians.
Tetrahedrons are 4-sided solids. A regular tetrahedron is the equilateral pyramid, having one pyramid as the base and three others the sides.
tetrahedrons
polymorphs
good question
tetra means four.
Two regular tetrahedrons connected face to face make a "regular triangular dipyramid." That is one of the 92 "Johnson solids." Those are the convex polyhedrons whose faces are regular polygons but do not belong to either of the two sets of highly symmetric polyhedrons (the Platonic and the Archimedean) or to the perhaps less interesting two infinite families of prisms and antiprisms. If the two tetrahedrons overlap, both centers at the same place but with the tetrahedrons facing in opposite directions, it makes a "stellated octahedron."
Silicate minerals.
The Stack class represents a last-in-first-out (LIFO) stack of objects. It extends class Vector with five operations that allow a vector to be treated as a stack. The usual push and pop operations are provided, as well as a method to peek at the top item on the stack, a method to test for whether the stack is empty, and a method to search the stack for an item and discover how far it is from the top.
More like two tetrahedrons stuck together.