Where is the Pentagon?
the Pentagon (in English: The Pentagon) is a building that is located in Arlington, Virginia, near Washington, the federal capital of the United States. This building houses the headquarters of the Department of Defense. In 2009, more than 26,000 people worked there, including civilians and soldiers.
The term ” Pentagon » derives from the Latin pentagonum of the same meaning, substantivation of the adjective pentagonus, itself borrowed from ancient Greek, πεντάγωνος (pentágônos), « pentagonal », « which has five angles, five sides ».
We appointed a polygon depending on the number of sides : where the triangle is a polygon who has three sides ; where the quadrilateral is a polygon who has four sides ; where the Pentagon is a polygon who has five sides ; ohhexagon is a polygon who is six sides ; where the heptagon is a polygon who is seven sides ; oh…
In the pentagon, we find two right triangles 36 – 54. They are joined by one side of the right angle to form two isosceles triangles (see figure below). The reference dimension is the hypotenuse of one of them: R = 1, the radius of the circumscribed circle of the pentagon.
Basic right triangle in the pentagon The two colored triangles in the figure are important because they allow the calculation of the lengths of the various segments included in the regular pentagon. Below are the main calculation elements. In the pentagon, there are two right triangles 36 – 54.
Construction of the Pentagon (view from the northwest), July 1, 1942. Fighting the fire caused by the attack of September 11, 2001. On the lawn, a piece of wreckage from American Airlines Flight 77.
Note the fundamental property of its diagonals: length equal to the golden number and cut diagonals inverse to the golden number (Illustration below). Angles of the regular pentagon SeeApproximation of the tangent of 72°/ of the sine of 36°/ Riddles with Diagonal angles and their cut in golden ratio / Nesting pentagons