`M = 1/4 * sqrt( 5*(5 + 2* sqrt(5)))* s^2 * h * mD`

Enter a value for all fields

This Weight of a Pentagon calculator computes the weight of a regular pentagon shaped objects with 5 equal sides of length, a height and the density of material. 

INSTRUCTIONS: Choose units and enter the following:

• (s) Length of Pentagon Sides
• (h) Height of Pentagon Shape
• (mD) Mean Density of Material

Weight of a Pentagon (M): The mass / weight is returned in kilograms.   However, this can be automatically converted to compatible units via the pull-down menu.

The Math / Science

The calculator first computes the volume of the pentagon shape.

The formula for the mass of a pentagon is:

    M =¼•√(5+2•√5)•s²•h•mD 

where:

• M = Mass of Pentagon 
• s = Side Length
• h = Height
• mD = Mean Density of Material

A regular pentagon has five equal sides and equal angles.  A pentagon volume is a pentagon shaped object with a regular pentagon cross-section (area) and perpendicular height.

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Mean Density Table

Common Mean Densities in Kilograms per Meter Cubed (kg/m3)
Fluids Pure Water - 1,000   Seawater - 1,022   Milk - 1,037  Olive Oil - 860 Cement Slurry - 1,442  Fuels Diesel Fuel - 885  Crude Oil - 870 to 920   Fuel Oil -  890   Ethanol - 789   Gasoline (petrol) - 737  Propane - 493  Liquid Natural Gas - 430 to 470  Market-Ready Grains Corn - 721 (56 lb/bu) Wheat - 772 (60 lb/bu) Barley - 618 (48 lb/bu) Oats - 412 (32 lb/bu) Rye - 721 (56 lb/bu) Soybean - 772 (60 lb/bu)	Metals Density of Aluminum - 2,700 Density of Brass - 8,530  Density of Bronze - 8,150  Density of Chromium - 7,190  Density of Cobalt - 8,746  Density of Copper - 8,940   Density of Gallium - 5907  Density of Gold - 19,300 Density of Iron - 7,847 Density of Lead - 11,340 Density of Nickle - 8,908  Density of Palladium -  12,023 Density of Platinum - 21,450  Density of Steel - 7,850  Density of Silver - 10,490  Density of Tin - 7,280 Density of Titanium - 4,500  Density of Tungsten - 19,600  Density of Uranium - 19,050 Density of Zinc - 7,135  Density of Zirconium - 6,570	Earthen Concrete - 2,371 Dirt - 1,250 Fire Clay - 1,362 Glass - 2,500 Granite - 2,691 Sand (dry) - 1,602 Sand (wet) - 2,082 Sandstone - 2,323 Synthetic Bakelite - 1,362 Carbon Fiber - 2,000 Organic Balsa - 170 Cork - 240 Mahogany - 545 Oak - 760 Pine - 539 Rubber - 1,522
Mean Density Lookup Function

Mean density is scientifically volume divided by mass.  There are  various unit for density adopted by cultures and industries. Common units for density included the following:

• kilograms per cubic meter (kg/m³)
• grams per cubic centimeter (g/cm³)
• grams per liter (g/L)
• pounds per cubic feet (lb/ft³)
• ounces per cubic inch (oz/in³)
• pounds per barrel (lb/bbl)
• pounds per bushel (lb/bu)

If you want to identify a material by its density, use the Density Within Range tool.

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Weight is technically the downward force that a mass exerts based on the force of gravity and the mass of the object.  On the surface of the Earth, mass and weight are often interchanged.  In some places, objects are sold by the gram (mass), and in other locations, the same objects are sold by the ounce (weight).

The Weight Calculators use the dimensions of an object and its shape to compute the objects volume.  They then apply a density associated with a material to estimate the objects weight.

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Weight Calculators

• Weight from Area, Height and Density
• Cube Weight 
• Box Weight
• Cone Weight
• Cone Frustum Weight
• Cylinder Weight
• Slanted Cylinder Weight
• Semicircle Weight
• Triangular Weight
• Quadrilateral Weight 
• Pentagon Weight 
• Hexagon Weight 
• Heptagon Weight
• Octagon Weight
• Nonagon Weight
• Decagon Weight
• Hendecagon Weight
• Dodecagon Weight
• Paraboloid Weight
• Polygon Pyramid Frustum Weight
• Sphere Mass
• Sphere Cap Weight
• Sphere Segment Weight
• Sphere Shell Mass
• Oblate Spheroid Mass
• Ellipsoid Weight
• Torus Weight
• Bottle Weight
• Bottle Content Weight
• Chamfer Weight
• Ring Weight