Polyhedra and Prisms — Worked Examples
These examples move from topological checks to direct and inverse prism calculations. Keep base geometry separate from the perpendicular distance between the parallel base planes.
Example 1: Verify Euler's formula for a cube
A cube has vertices, edges, and faces. Verify Euler's formula.
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0 of 2 Steps CompletedExample 2: Recover an unknown face count using Euler's formula
A convex polyhedron has vertices and edges. Determine the number of faces.
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0 of 2 Steps CompletedExample 3: Volume and total area of a rectangular prism
A closed rectangular prism measures . Determine its volume and total surface area.
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0 of 3 Steps CompletedExample 4: Right-triangular prism
A right-triangular prism has base legs and and prism height . Determine its volume and total surface area.
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0 of 3 Steps CompletedExample 5: Oblique prism volume uses perpendicular height
An oblique prism has base area , perpendicular height , and lateral edges long. Determine its volume.
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A prism has constant base area and must enclose . Determine the required perpendicular height.
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A concrete cube has side length . Determine its volume and total surface area.
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A cube has total surface area . Determine its side length and volume.
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A cube side is doubled. Determine the factors by which its total surface area and volume change.
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0 of 2 Steps CompletedExample 10: Truncated triangular prism from vertex heights
A triangular base has area . A plane cuts a right prism so the three heights measured at the base vertices are , , and . Determine the volume when the cutting-plane height varies linearly over the triangular base.
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A rectangular concrete block is . If concrete density is , estimate its mass.
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A rectangular prism has base dimensions and height . A right-triangular prism has base legs and and the same height. Compare their volumes.
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0 of 2 Steps CompletedPrism calculation check
For oblique prisms, do not substitute lateral-edge length for perpendicular height. For surface area, verify whether the prism is right or oblique before using as the lateral area. Topological counts such as , , and are dimensionless and should not be mixed with geometric volume notation without context.