The Dungeness National Wildlife Refuge is located near the town of Sequim in Clallam County in the U.S. state of Washington , on the Strait of Juan de Fuca . The refuge is composed of 772.52 acres (312.63 ha) which include Dungeness Spit , Graveyard Spit, and portions of Dungeness Bay and Harbor. Dungeness Spit is one of the world's longest natural sand spits, 6.8 miles (10.9 km) long and very narrow. A lighthouse , the New Dungeness Light , built in 1857, is located near the end of the spit. Access to Dungeness Spit is through a Clallam County Park which has hiking trails, picnic areas, and a campground. On January 20, 1915, it was designated as a National Wildlife Refuge by President Woodrow Wilson . Dungeness is one of six refuges in the Washington Maritime National Wildlife Refuge Complex .
17-476: The refuge provides habitat for a variety of wildlife species with more than 250 species of birds and 41 species of land mammals. The bay and estuary of the Dungeness River supports Waterfowl , Wader , Shellfish , and harbor seals . Anadromous fish like Chinook , Coho , pink salmon and chum salmon occur in the waters of Dungeness Bay and Harbor. A number of species of waterfowl stop briefly in
34-465: A and b , and then connecting their common endpoint to the semicircle with a segment perpendicular to the diameter. The length of the resulting segment is the geometric mean. This can be proven by applying the Pythagorean theorem to three similar right triangles, each having as vertices the point where the perpendicular touches the semicircle and two of the three endpoints of the segments of lengths
51-477: A and b . The construction of the geometric mean can be used to transform any rectangle into a square of the same area, a problem called the quadrature of a rectangle. The side length of the square is the geometric mean of the side lengths of the rectangle. More generally, it is used as a lemma in a general method for transforming any polygonal shape into a similar copy of itself with the area of any other given polygonal shape. The Farey sequence of order n
68-402: A semicircle is a one-dimensional locus of points that forms half of a circle . It is a circular arc that measures 180° (equivalently, π radians , or a half-turn ). It only has one line of symmetry ( reflection symmetry ). In non-technical usage, the term "semicircle" is sometimes used to refer to either a closed curve that also includes the diameter segment from one end of the arc to
85-441: A bay often reduces the strength of winds and blocks waves . Bays may have as wide a variety of shoreline characteristics as other shorelines. In some cases, bays have beaches , which "are usually characterized by a steep upper foreshore with a broad, flat fronting terrace". Bays were significant in the history of human settlement because they provided easy access to marine resources like fisheries . Later they were important in
102-453: A bay unless its area is as large as (or larger than) that of the semi-circle whose diameter is a line drawn across the mouth of that indentation — otherwise it would be referred to as a bight . There are various ways in which bays can form. The largest bays have developed through plate tectonics . As the super-continent Pangaea broke up along curved and indented fault lines, the continents moved apart and left large bays; these include
119-611: Is also used for related features , such as extinct bays or freshwater environments. A bay can be the estuary of a river, such as the Chesapeake Bay , an estuary of the Susquehanna River . Bays may also be nested within each other; for example, James Bay is an arm of Hudson Bay in northeastern Canada . Some large bays, such as the Bay of Bengal and Hudson Bay, have varied marine geology . The land surrounding
136-423: Is the sequence of completely reduced fractions which when in lowest terms have denominators less than or equal to n , arranged in order of increasing size. With a restricted definition, each Farey sequence starts with the value 0, denoted by the fraction 0 / 1 , and ends with the fraction 1 / 1 . Ford circles can be constructed tangent to their neighbours, and to
153-533: The Gulf of Guinea , the Gulf of Mexico , and the Bay of Bengal , which is the world's largest bay. Bays also form through coastal erosion by rivers and glaciers . A bay formed by a glacier is a fjord . Rias are created by rivers and are characterised by more gradual slopes. Deposits of softer rocks erode more rapidly, forming bays, while harder rocks erode less quickly, leaving headlands . Semi-circle In mathematics (and more specifically geometry ),
170-497: The United States Fish and Wildlife Service . Bay A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean , a lake , or another bay. A large bay is usually called a gulf , sea , sound , or bight . A cove is a small, circular bay with a narrow entrance. A fjord is an elongated bay formed by glacial action. The term embayment
187-535: The Dungeness area each fall on their way south for the winter and again when they head north in the spring. Many species of waterfowl winter in the area. Dungeness Bay and Harbor support black brant , present from late October through early May, with peak numbers of approximately 3,000-5,000 in April. Shorebirds and water waders feed and rest along the water’s edge. Harbor seals haul out to rest and give birth to pups on
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#1732801371283204-432: The center of the circle containing the given semicircle. A semicircle can be used to construct the arithmetic and geometric means of two lengths using straight-edge and compass. For a semicircle with a diameter of a + b , the length of its radius is the arithmetic mean of a and b (since the radius is half of the diameter). The geometric mean can be found by dividing the diameter into two segments of lengths
221-527: The development of sea trade as the safe anchorage they provide encouraged their selection as ports . The United Nations Convention on the Law of the Sea defines a bay as a well-marked indentation in the coastline, whose penetration is in such proportion to the width of its mouth as to contain land-locked waters and constitute more than a mere curvature of the coast. An indentation, however, shall not be regarded as
238-636: The end of Dungeness Spit. The tideflats support crabs, clams, and other shellfish. Dungeness NWR is recognized as an Important Bird Area by the National Audubon Society. The Refuge is internationally significant because many of the birds that stop here breed as far north as Alaska and migrate as far south as South America. The Dungeness area is additionally important as a spring staging area (a place where large groups of birds stop to build up their fat reserves for migration) for black brant and other waterfowl. The main activities occurring on
255-443: The other or to the half- disk , which is a two-dimensional geometric region that further includes all the interior points. By Thales' theorem , any triangle inscribed in a semicircle with a vertex at each of the endpoints of the semicircle and the third vertex elsewhere on the semicircle is a right triangle , with a right angle at the third vertex. All lines intersecting the semicircle perpendicularly are concurrent at
272-420: The refuge are wildlife observation and photography, and wildlife education and interpretation. To ensure that wildlife continue to have a place to rest and feed, some recreational activities such as jogging, swimming, and other beach activities are allowed only in selected areas during certain times of the year. [REDACTED] This article incorporates public domain material from websites or documents of
289-401: The x-axis at these points. Semicircles joining adjacent points on the x-axis pass through the points of contact at right angles. The equation of a semicircle with midpoint ( x 0 , y 0 ) {\displaystyle (x_{0},y_{0})} on the diameter between its endpoints and which is entirely concave from below is If it is entirely concave from above,
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