Pentagonal Prism Calculator
Calculate the volume, surface area, lateral area, edge, and length of a regular pentagonal prism.
How to Calculate Pentagonal Prism Dimensions
A regular pentagonal prism is a three-dimensional solid with two parallel regular pentagonal bases and five rectangular lateral sides. It is defined by the base edge length a and the prism height/length L.
Regular Pentagonal Prism Formulas
The formulas below assume a regular pentagon base:
- Base Area (Ab):
Ab = 0.25 * √(25 + 10√5) * a² ≈ 1.720477 * a² - Volume (V):
V = Ab * L ≈ 1.720477 * a² * L - Lateral Surface Area (Slat):
Slat = 5 * a * L - Total Surface Area (S):
S = 2 * Ab + Slat ≈ 3.440955 * a² + 5 * a * L - Apothem (incircle radius):
apothem ≈ 0.688191 * a
Step-by-Step Worked Example
Calculate the properties of a pentagonal column with a base edge of 2 m and a height of 5 m:
- Base Area: 1.720477 * 2² = 1.720477 * 4 ≈ 6.8819 m²
- Volume: 6.8819 * 5 ≈ 34.41 m³
- Lateral Area: 5 * 2 * 5 = 50 m²
- Total Surface Area: 2 * 6.8819 + 50 = 13.7638 + 50 ≈ 63.764 m²
Also check: Pentagon Calculator, Hexagonal Prism Calculator, Rectangular Prism Calculator, Triangular Prism Calculator, Volume Calculator, Surface Area Calculator.
Frequently Asked Questions
How do you find the volume of a pentagonal prism?
Multiply the area of the regular pentagonal base by the prism length/height. The volume formula is: V = 1.720477 * a² * L, where a is the base edge length and L is the prism height.
What is the difference between lateral and total surface area?
Lateral surface area measures only the area of the 5 rectangular side faces: 5 * a * L. Total surface area includes the lateral area plus the area of the two pentagonal end caps: 2 * Ab + 5 * a * L.
How many faces, edges, and vertices does a pentagonal prism have?
A pentagonal prism has 7 faces (2 bases + 5 lateral sides), 15 edges (5 on each base + 5 connecting them), and 10 vertices (5 on each base).
How is the golden ratio related to a pentagonal prism?
Since the cross-section is a regular pentagon, the diagonals of its bases are related to its edge lengths by the Golden Ratio (φ ≈ 1.618034). Specifically, diagonal = a * φ.