Three dimensional objects or solids generally have length, breadth and height. Three dimensional objects look different from different locations or angles.
- A polyhedron is a solid shape bounded by polygons whereas non-polyhedrons do not have polygon shaped faces.
- Cubes, cuboids, prisms, and pyramids are few examples of polyhedrons.
- Spheres, cones and cylinders are a few examples of non-polyhedrons.
- The polygonal regions forming the polyhedron are known as its faces, two intersecting faces meet at a line segment called an edge and three edges meet at a point called the vertex.
- F+V=E+2 is known as Euler’s formula and it holds true for any polyhedron. Here F stands for faces, V for vertices and E for the edges of the polyhedron.
- A polyhedron is said to be regular if its faces are made up of regular polygons and the same number of faces meet at each vertex.
- An irregular polyhedron is made of polygons whose sides and angles are not of equal measure.
- In a convex polyhedron, the line segment joining any two points on the surface of the polyhedron lies entirely inside or on the polyhedron.
- A polyhedron some of whose plane sections are concave polygons is known as a concave polyhedron. Concave polygons have at least one interior angle greater than 180° and has some of its sides bent inward.
- A prism is a polyhedron with parallel congruent polygon bases and sides made of parallelograms.
- A pyramid is a polyhedron whose base is a polygon of any number of sides and whose lateral faces are triangles with a common vertex.
- Prisms and pyramids are named after the shape of their base.
- Maps represent the location of a place or object in relation to other places or objects.
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