An eightsided shape is called an octagon.
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A 5 sided shape is called a pentagon. The interior angles of a pentagon add up to 540 degrees. A pentagon is a polygon. The most famous pentagon is The Pentagon in Washington, D.C
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A 2dimensional 8sided shape is called an octagon. A 3dimensional 8sided shape is called
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A tetrahedron is one of the five Platonic solids, since it is a pyramid made up of four equal triangles. But a squarebottomed pyramid is not a tetrahedron, since it also includes
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