Quadrilateral four sided

S = arc length subtended by 0 L = chord length subtended by 0 H = maximum rise of arc above chord, r-H = d 0 = central angle (rad) subtended by arc S 

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Quadrilateral (four-sided) A = V2ah sin 0 where a, h are the lengths of the diagonals and the acute angle between them is 0. Regular Polygon of n Sides See Fig. 3-4. 

A quadrilateral is a four-sided polygon determined by four coplanar points (three of which are noncollinear), if the line segments thus formed intersect each other only at their end points, forming four angles. 

Four-sided polygons are called quadrilaterals and like triangles, there are classifications for quadrilaterals. 

A quadrilateral is a four-sided polygon. Since a quadrilateral can be divided by a diagonal into two triangles, the sum of its angles will equal 180 + 180 = 360 degrees. 

The interior angles of any four-sided figure, or quadrilateral, add up to 360°. 

To break the domain into a set of discrete subdomains, or computational cells, or control volumes, a grid is used. Also called a mesh, the grid can contain elements of many shapes and sizes. In 2D domains, for example, the elements are usually either quadrilaterals or triangles. In 3D domains (Figure 5-3), they can be tetrahedra (with four sides), prisms (five sides), pyramids (five sides), or hexahedra (six sides). A series of line segments (2D) or planar faces (3D) connecting the boundaries of the domain are used to generate the elements. 

There exists a complete quadrilateral (Figure 3.7) which is a set of four lines (sides) intersecting in pairs in six distinct points... 

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