Calculations at an elongated semicircle, a semicircle with a matching rectangle attached to the flat side. At the connection of the semicircle and the rectangle, the vertices disappear.
Enter semicircle radius and rectangle length and choose the number of decimal places. Then click Calculate.
Formulas:
pi:
Radius, lengths, breadth and perimeter have the same unit (e.g. meter), the area has this unit squared (e.g. square meter).
A semicircle can be straight elongated indefinitely without forming vertices, since the tangents at two opposite points are parallel. And a semicircle is simply a circle divided through two opposite points. The two straight sides of the extended semicircle then lie along these tangents. Vertices only arise when these straight sides are reconnected, in this instance, by a side perpendicular to these two.
The elongated semicircle corresponds to a vertically bisected stadium shape. A horizontally bisected stadium shape is a half-stadium. The elongated semicircle can, in turn, be bisected into two elongated quarter circles. When a circle or a semicircle is divided down the middle, the result is two congruent parts, just as is the case with a rectangle. When the elongated semicircle is divided, however, the result is two mirror-image parts that are not congruent. This property is called chirality, which signifies handedness. The line along which the elongated semicircle is divided down the middle also serves as its axis of symmetry. Apart from this axial symmetry with respect to this line, this shape possesses no other symmetries.
The three-dimensional equivalent of this shape, that is the solid of revolution generated by rotating it around its axis of symmetry, is the elongated hemisphere.
This form is relatively common in architecture and design. Windows and doors, particularly on prestigious buildings, may take this shape, as can archways. Such windows and doors may consist of a single unit or be composed of two wings, which then take the form of elongated quarter-circles.