A prism's bases not only define its overall shape, but also indicate the number of faces, vertices and edges it has. A prism, a three-dimensional solid and a polyhedron subtype, possesses two identical and parallel polygons as its bases, held apart by a specified distance. The prism's faces are the two-dimensional shapes that make up its surface, its edges are the line-segments that make up the face's perimeters, and the vertices are the points where the edges meet. A decagonal prism has bases that are decagons, with the decagon's 10 sides determining the number of faces, vertices and edges of the prism.
Instructions
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1
Count the number of sides one of the bases has and then add 2 --- the number of bases --- to determine the prism's number of faces. A decagon has 10 sides, so a decagonal prism will have 12 faces.
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2
Multiply the base's number of sides by 2 to determine the prism's number of vertices. Ten multiplied by 2 results in 20 --- a decagonal prism will have 20 vertices.
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3
Multiply the base's number of sides by 3 to determine the prism's number of edges. Ten multiplied by 3 results in 30 --- a decagonal prism will have 30 edges.