Pentagonal Pyramid Calculator

Calculate volume, surface area, and other properties of a pentagonal pyramid

← to Pyramid Calculator

Calculation Results

Enter pentagonal pyramid measurements to calculate all properties.

Pentagonal Pyramid Diagram

h = 0 a = 0 V = 0

Pentagonal Pyramid Formulas

Key Properties

  • Base Area (B): Area of the pentagonal base
  • Height (h): Perpendicular distance from base to apex
  • Volume (V): Space contained within the pyramid
  • Lateral Area (L): Area of the five triangular faces
  • Surface Area (A): Total area including the base
  • Base Perimeter (P): Perimeter of the pentagonal base
  • Slant Height (l): Height of the triangular faces
  • Apothem (ap): Distance from center to midpoint of a base side

Calculation Formulas

  • Base Area (Regular): B = (5/4) × a² × cot(π/5)
  • Base Area (General): B = (5/2) × a × ap
  • Volume (V): V = ⅓ × B × h
  • Surface Area (A): A = B + L
  • Base Perimeter (P): P = 5 × a
  • Regular Pentagon Apothem: ap = a / (2 × tan(π/5))
  • Slant Height (Regular): l = √(h² + ap²)
  • Lateral Area (Regular): L = (5/2) × a × l

Where:   a = base side length,   h = height of pyramid,   ap = apothem of base,   l = slant height

Example Calculation

For a regular pentagonal pyramid with:

Edge length (a) = 6 units, Height (h) = 8 units.

Calculations:

  • Apothem ≈ 6 / (2 × tan(36°)) ≈ 4.13 units
  • Base Area ≈ (5/4) × 6² × cot(36°) ≈ 61.94 units²
  • Base Perimeter = 5 × 6 = 30 units
  • Volume ≈ ⅓ × 61.94 × 8 ≈ 165.17 units³
  • Slant Height ≈ √(8² + 4.13²) ≈ 8.99 units
  • Lateral Area ≈ (5/2) × 6 × 8.99 ≈ 134.85 units²
  • Surface Area ≈ 61.94 + 134.85 ≈ 196.79 units²

About Pentagonal Pyramids

A pentagonal pyramid is a three-dimensional shape with a pentagonal base and five triangular faces meeting at a common apex. It has 6 faces, 10 edges, and 6 vertices. When the base is a regular pentagon and the apex is directly above the center, it's called a regular pentagonal pyramid.

Real-World Applications

  • Architecture: Some decorative roof elements and spires
  • Design: Unique geometric sculptures and art pieces
  • Chemistry: Molecular structures with pentagonal symmetry
  • Mathematics: Study of polyhedrons and geometry

Types of Pentagonal Pyramids

  • Regular Pentagonal Pyramid: Base is a regular pentagon, apex directly above center
  • Irregular Pentagonal Pyramid: Base is an irregular pentagon
  • Right Pentagonal Pyramid: Apex is directly above the base's centroid
  • Oblique Pentagonal Pyramid: Apex is not aligned with the base's centroid

Pentagonal Pyramid Components

B a

Base Area (B)
B = (5/2) × a × ap

h

Pyramid Height (h)

L

Lateral Area (L)
L = (5/2) × a × l

A

Surface Area (A)
A = B + L

P

Base Perimeter (P)
P = 5 × a

V

Volume (V)
V = ⅓ × B × h

How to Use the Pentagonal Pyramid Calculator

The Pentagonal Pyramid Calculator helps compute various properties based on input values. Here's how to use it:

1. Select Calculation Method

Choose what measurements you know:

  • Base Dimensions & Height - Enter base side length, apothem and pyramid height
  • Base Area & Height - When you know the base area
  • Volume & Base Area - To find the pyramid height
  • Surface Area - When you know total surface area
  • Regular Pentagon - When base is a regular pentagon

2. Enter Your Values

Input positive numbers in the appropriate fields:

Example 1: Side length = 6, Apothem = 4.13, Height = 8

Example 2: Edge length = 6, Height = 8 (for regular pentagon)

3. Get Results

The calculator will compute all properties:

  • Base Area (B)
  • Pyramid Height (h)
  • Volume (V)
  • Lateral Area (L)
  • Surface Area (A)
  • Base Perimeter (P)
  • Slant Height (l)
  • Apothem (ap)

Practical Applications

  • Calculate material needed for pentagonal pyramid structures
  • Determine paint required for pyramid-shaped objects
  • Find storage capacity of pentagonal pyramid containers
  • Solve geometry problems involving pentagonal pyramids

Pentagonal Pyramid Formulas

Parameter Formula Description
Base Side Length (a) Given Length of pentagon's side
Base Area (Regular) (5/4) × a² × cot(π/5) Area of regular pentagonal base
Base Area (General) (5/2) × a × ap Area using side length and apothem
Height (h) Given or calculated Height from apex to base
Volume (V) (B × h)/3 Volume of the pyramid
Apothem (Regular) a / (2 × tan(π/5)) Distance from center to side midpoint
Slant Height (Regular) √(h² + ap²) Height of triangular faces
Lateral Area (Regular) (5/2) × a × l Sum of areas of the 5 lateral faces
Surface Area (A) B + L Total surface area (base + lateral)
Base Perimeter (P) 5 × a Perimeter of the base

Frequently Asked Questions

1. What's the difference between a pentagonal pyramid and a pentagonal prism?

A pentagonal pyramid has a pentagonal base and triangular faces meeting at an apex, while a pentagonal prism has two pentagonal bases connected by rectangular faces.

2. How many faces does a pentagonal pyramid have?

A pentagonal pyramid has 6 faces - one pentagonal base and five triangular lateral faces.

3. How do you find the slant height if you know height and apothem?

Use the formula: l = √(h² + ap²) where h is height and ap is apothem.