surface area formula for equilateral triangular prism

Right and oblique tetrahedronsĪ right tetrahedron is one in which the apex is directly above the center of the base. The two triangles, shaded in blue, formed by cross sections parallel to the base of the tetrahedron above, are similar (same shape but not the same size) to the tetrahedron's triangular base. It is the polyhedron that can be formed with the fewest number of faces.Īny cross section that is parallel to the base of a tetrahedron forms a triangle that is similar to its base. A tetrahedron has 4 faces, 6 edges, and 4 vertices. An edge is a line segment formed by the intersection of two adjacent faces. We usually think of the apex as the 'top' of the tetrahedron. The lateral faces share a common vertex called the apex. Properties of a tetrahedronĪ tetrahedron is a pyramid with one triangular base and three triangular sides, called lateral faces. Note that this is not the only possible tetrahedron net. A regular tetrahedron net is shown below:Įach of the outer triangles folds inwards to form the tetrahedron. The tetrahedron is the smallest Platonic solid.Ī net in geometry is a 2D pattern of polygons that can be modified to form the polyhedron, which in this case is a tetrahedron.The tetrahedron is the only Platonic solid with no parallel faces.The same number of faces meet at each vertex.All four faces are equilateral triangles.Also, all 4 vertices are the same distance from each other. A regular tetrahedron has the following properties:

Often, when a tetrahedron is referred to as 'the' tetrahedron, the tetrahedron being referenced is the Platonic solid. Regular tetrahedronĪ regular tetrahedron is the type of tetrahedron referred to as a Platonic solid. The tetrahedron is one of 5 Platonic solids (a Platonic solid is a polyhedron in which all faces are congruent regular polygons and the same number of faces meet at each vertex). If all of the triangles that form the tetrahedron are congruent equilateral triangles, the tetrahedron is referred to as a regular tetrahedron. It is also known as a triangular pyramid. Below is a tetrahedron example.Ī tetrahedron is a three-dimensional ( 3D) figure made up of 4 triangular faces. Home / geometry / shape / tetrahedron TetrahedronĪ tetrahedron is a space figure with four triangular faces.

Surface area formula for equilateral triangular prism