Those are the pyramids.
None, because there can be no such thing as a triangular square. If it is triangular it cannot be a square, if it is a square it cannot be triangular.
Uper-triangular Matrix A square matrix A whose elements aij=0 for i>j is called upper triangular matrix.
A triangular pyramid has a triangular base and three triangular faces meeting at its apex. A square pyramid has a square base and four triangular faces meeting at its apex.
square pyramid
A solid figure with five faces is called a pyramid. Specifically, a triangular pyramid, or tetrahedron, has four triangular faces, while a square pyramid has one square base and four triangular faces, totaling five. The pyramid's faces meet at a single point called the apex.
Both the Egyptians and the Maya/Aztec built large pyramids with triangular sides and square bases.
The solid shape that has one square face and four triangular faces is called a pyramid. If you were to have a shape that had four triangular faces and no square face, it would be called a triangular pyramid.
It's a pyramid.
None, because there can be no such thing as a triangular square. If it is triangular it cannot be a square, if it is a square it cannot be triangular.
A set-square.
Uper-triangular Matrix A square matrix A whose elements aij=0 for i>j is called upper triangular matrix.
A pyramid with a square base is called a square pyramid. It is a three-dimensional shape that has a square as its base and four triangular faces that meet at a point called the apex.
trapezoid
A triangular pyramid has a triangular base and three triangular faces meeting at its apex. A square pyramid has a square base and four triangular faces meeting at its apex.
square pyramid
The area of Angram Bottoms is 98,000.0 square meters.
Trapezoidal, actually. But the square sails were called square sails. Lateen or square could be referred to as yards.