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Rhombus

math Maturity 5-7

A rhombus is a shape.

Rhombus1.svg
Rhombus1.svg
It has four sides. All sides are the same length. Some people call it a diamond. You can see it on playing cards. It is a fun shape to find. Can you see a diamond shape?

42 words

A rhombus is a special shape.

Rhombus1.svg
Rhombus1.svg
It has four sides. All four sides are the same length. You might know it as a diamond. You can see it on playing cards.

Some people call it a lozenge. A calisson is a sweet shaped like this. It is a French treat.

A rhombus can also be a square. This happens if all corners are right angles.

This shape has two lines inside. These lines are called diagonals. They cross each other at a right angle.

Lattice of rhombuses.svg
Lattice of rhombuses.svg

88 words

A rhombus is a special four-sided shape.

Rhombus1.svg
Rhombus1.svg
All four of its sides are the same length. This makes it an equilateral quadrilateral. You might know it as a diamond. You can see this shape on playing cards. Some people call it a lozenge. In France, a sweet treat is called a calisson. It has that same shape.

A rhombus is a type of parallelogram. This means its opposite sides are parallel. It is also a type of kite. If a rhombus has four right angles, it is a square.

Symmetries of square.svg
Symmetries of square.svg

Inside the shape, two lines connect opposite corners. These are called diagonals. The diagonals cross at a right angle. They also cut each other exactly in half. This makes the shape very balanced. You can even fit a circle inside a rhombus. The circle will touch all four sides.

Rhombicdodecahedron.jpg
Rhombicdodecahedron.jpg

Rhombuses can also make 3D shapes. A rhombohedron is a 3D shape with rhombuses for faces. Some shapes use many rhombuses. For example, a rhombic dodecahedron has 12 faces. A rhombic icosahedron has 20 faces.

178 words

A rhombus is a special kind of four-sided shape.

Rhombus1.svg
Rhombus1.svg
In geometry, we call it an equilateral quadrilateral. This means all four of its sides are the same length. You might know this shape as a diamond. This name comes from the shape of a diamond gemstone. You can also see this shape on playing cards. Some people call it a lozenge or a calisson. A calisson is a type of sweet treat from France. These names help us describe how the shape looks in our world.

There are many ways to describe how a rhombus works. It is a type of parallelogram because its opposite sides are parallel. It is also a type of kite. If you make a rhombus with four right angles, it becomes a square.

Symmetries of square.svg
Symmetries of square.svg
Inside the shape, two lines called diagonals connect the opposite corners. These diagonals cross each other at a right angle. They also cut each other exactly in half. Because of this, you can fit a circle inside a rhombus so it touches all four sides.

People have studied these shapes for a very long time. The name rhombus comes from a Greek word. It means something that spins, like an ancient toy. Great thinkers like Euclid and Archimedes used this word. Archimedes even used the term "solid rhombus" to describe a shape made of two cones.

Rhombicdodecahedron.jpg
Rhombicdodecahedron.jpg
These early mathematicians helped us understand how flat shapes can relate to 3D objects. Their work shows us how math connects different ideas together.

Math lets us use numbers to find the size of a rhombus. You can find the area by multiplying the base by the height. You can also find it using the diagonals. If the diagonals are lengths p and q, the area is half their product.

Lattice of rhombuses.svg
Lattice of rhombuses.svg
We can also use the side length and an angle to find the area. There are many ways to measure these shapes. Each way uses different parts of the rhombus to find the same answer.

Rhombuses can also build amazing three-dimensional shapes. A rhombohedron is a 3D figure that uses rhombuses for its faces. Some shapes are very complex. A rhombic dodecahedron has 12 faces that are all the same.

Rhombicdodecahedron.jpg
Rhombicdodecahedron.jpg
A rhombic icosahedron has 20 faces. There is even a rhombic enneacontahedron with 90 faces.
Rhombic enneacontahedron.svg
Rhombic enneacontahedron.svg
These shapes show how simple sides can build huge and beautiful patterns in space.

404 words

A rhombus is a specific type of four-sided shape known as an equilateral quadrilateral. This means that all four of its sides have the exact same length. In geometry, it is classified as a simple polygon because its sides do not cross each other. A rhombus is also a special case of two other shapes: the parallelogram and the kite. While all rhombuses are parallelograms, not all parallelograms are rhombuses. If a rhombus happens to have four right angles, it becomes a square.

Rhombus1.svg
Rhombus1.svg

To understand how a rhombus works, we can look at its internal structure. Every rhombus has two diagonals that connect its opposite corners. These diagonals possess unique mathematical properties. First, they are perpendicular, meaning they cross at a right angle. Second, they bisect each other, which means they cut one another into two equal parts. The diagonals also bisect the interior angles of the rhombus. Because of these features, a rhombus is considered an orthodiagonal quadrilateral. It is also a tangential quadrilateral, which means you can fit an inscribed circle inside it that touches all four sides.

Rhombus1.svg
Rhombus1.svg

There are several ways to identify a rhombus based on its properties. You can define it as a parallelogram where at least two consecutive sides are equal in length. Another way is to describe it as a parallelogram where the diagonals are perpendicular. You can also identify one by looking at its angles. A non-square rhombus typically has two opposite acute angles and two opposite obtuse angles. Mathematically, if you have a quadrilateral where the diagonals are perpendicular and bisect each other, you have found a rhombus.

Rhombus1.svg
Rhombus1.svg

The history of the word "rhombus" leads back to ancient Greece. The name comes from a Greek word meaning something that spins, like a bullroarer or an early version of a whirligig. Famous mathematicians like Euclid and Archimedes used this term in their work. Archimedes even used the phrase "solid rhombus" to describe a bicone. A bicone is a three-dimensional shape made of two right circular cones that share a common base. A flat rhombus can actually be seen as a cross section of such a shape.

Rhombus1.svg
Rhombus1.svg

We can use different mathematical formulas to calculate the size of a rhombus. The area, often called K, can be found by multiplying the base by the height. Another common method is to use the diagonals, p and q. The area is equal to half the product of these two diagonals. You can also find the area using the side length and the sine of one of the vertex angles. If you know the inradius, or the radius of the inscribed circle, you can multiply the semiperimeter by that radius to find the area.

Rhombus1.svg
Rhombus1.svg

Rhombuses appear in many different names and contexts in our culture. The term "diamond" comes from the shape of an octahedral diamond gemstone. In playing cards, the diamond suit was originally called "carreaux" in French. Some people use the term "lozenge," which might relate to almond pastries or the shape of tombstones. In France, a "calisson" is a sweet treat shaped like a rhombus. In certain mathematical patterns, a diamond is specifically a rhombus with a 60-degree angle.

Haltern am See, Naturpark Hohe Mark, Hohemarkenbusch, Baumstamm -- 2024 -- 4411 (kreativ 2).jpg
Haltern am See, Naturpark Hohe Mark, Hohemarkenbusch, Baumstamm -- 2024 -- 4411 (kreativ 2).jpg

Beyond flat shapes, rhombuses create complex three-dimensional structures called polyhedra. A rhombohedron is a 3D figure where the faces are rhombi. Some polyhedra are very large and intricate. A rhombic dodecahedron has 12 congruent rhombic faces. A rhombic triacontahedron features 30 golden rhombi, which are rhombi where the diagonals follow the golden ratio. Other shapes include the rhombic icosahedron with 20 faces and the rhombic enneacontahedron with 90 faces.

Rhombicdodecahedron.jpg
Rhombicdodecahedron.jpg
Rhombictriacontahedron.svg
Rhombictriacontahedron.svg
Rhombic icosahedron.svg
Rhombic icosahedron.svg
Rhombic enneacontahedron.svg
Rhombic enneacontahedron.svg

Finally, rhombuses are important in the study of patterns and lattices. They can tile a two-dimensional plane edge-to-edge in several ways. One such pattern is the rhombille tiling, which uses 60-degree rhombuses. There is also a rhombic lattice, which is a type of centered rectangular lattice. These patterns show how a single simple shape can repeat to fill an entire space perfectly.

Lattice of rhombuses.svg
Lattice of rhombuses.svg

685 words
🖼️ Images & Media (12)
File:Symmetries of square.svg
Symmetries of square.svg
File:Haltern am See, Naturpark Hohe Mark, Hohemarkenbusch, Baumstamm -- 2024 -- 4411 (kreativ 2).jpg
Haltern am See, Naturpark Hohe Mark,...
File:Rhombus1.svg
Rhombus1.svg
File:Lattice of rhombuses.svg
Lattice of rhombuses.svg
File:Isohedral tiling p4-51c.svg
Isohedral tiling p4-51c.svg
File:Rhombic star tiling.svg
Rhombic star tiling.svg
File:TrigonalTrapezohedron.svg
TrigonalTrapezohedron.svg
File:Rhombicdodecahedron.jpg
Rhombicdodecahedron.jpg
File:Rhombictriacontahedron.svg
Rhombictriacontahedron.svg
File:Rhombic icosahedron.svg
Rhombic icosahedron.svg
File:Rhombic enneacontahedron.svg
Rhombic enneacontahedron.svg
File:Rhombohedron.svg
Rhombohedron.svg
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