Three Dimensional Shapes
Objects with fixed shape, size, and occupying fixed space are called solids. Solid figures have three dimensions - length, breadth and height.  e.g. A ball, a brick, an ice cream cone and a can. Face The flat surface of a solid shape is called a face. Edge Any two adjacent faces of a solid shape meet on a line segment called an edge. Vertex A vertex of a solid shape is a point where three or more edges meet. A solid bounded by six rectangular faces is called a cuboid. A cuboid has 6 faces, 12 edges and 8 vertices.  A solid bounded by six square faces is called a cube. A solid whose bases are parallel plane polygons and the lateral faces are rectangles is called a prism. A pyramid is a solid whose base is a plane rectilinear figure whose lateral faces are triangles with a common vertex, called the vertex of the pyramid. Prisms and pyramids are named after their bases. The base of a prism can be of any polygonal shape such as triangle and square. A prism with two congruent triangles as bases which are parallel to each other and three lateral rectangular faces is a Triangular prism. There are 5 faces, 9 edges and 6 vertices in a triangular prism. There are 4 faces, 6 edges and 4 vertices in a triangular pyramid. A cylinder has two circular plane surfaces at its base and top. It has a curved surface in the middle. A cylinder has 2 flat faces, 1 curved surface and 2 edges. There are no vertices in a cylinder. A cone has 1 flat face and 1 curved surface. There are 1 edge and 1 vertex. The ball-like shape is called a sphere. A sphere has one curved surface, no edge and no vertex.

Summary

Objects with fixed shape, size, and occupying fixed space are called solids. Solid figures have three dimensions - length, breadth and height.  e.g. A ball, a brick, an ice cream cone and a can. Face The flat surface of a solid shape is called a face. Edge Any two adjacent faces of a solid shape meet on a line segment called an edge. Vertex A vertex of a solid shape is a point where three or more edges meet. A solid bounded by six rectangular faces is called a cuboid. A cuboid has 6 faces, 12 edges and 8 vertices.  A solid bounded by six square faces is called a cube. A solid whose bases are parallel plane polygons and the lateral faces are rectangles is called a prism. A pyramid is a solid whose base is a plane rectilinear figure whose lateral faces are triangles with a common vertex, called the vertex of the pyramid. Prisms and pyramids are named after their bases. The base of a prism can be of any polygonal shape such as triangle and square. A prism with two congruent triangles as bases which are parallel to each other and three lateral rectangular faces is a Triangular prism. There are 5 faces, 9 edges and 6 vertices in a triangular prism. There are 4 faces, 6 edges and 4 vertices in a triangular pyramid. A cylinder has two circular plane surfaces at its base and top. It has a curved surface in the middle. A cylinder has 2 flat faces, 1 curved surface and 2 edges. There are no vertices in a cylinder. A cone has 1 flat face and 1 curved surface. There are 1 edge and 1 vertex. The ball-like shape is called a sphere. A sphere has one curved surface, no edge and no vertex.

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