Special right triangle : , which follows immediately from the Pythagorean theorem. Of all right triangles, the 45°–45°–90° degree triangle has the smallest ratio of the hypotenuse to the sum of the legs, namely . Of all right triangles, the 45°–45°–90° degree triangle has the greatest ratio of the altitude from the hypotenuse to the sum of the legs, namely . Triangles with these angles are the only possible right triangles that are also isosceles triangles in Euclidean geometry. However, in spherical geometry and hyperbolic geometry, there are infinitely many different shapes of right isosceles triangles. This is a triangle whose three angles
Manezhnaya Square, Saint Petersburg Manezhnaya Square, Saint Petersburg Manezhnaya Square (, romanized "Manezhnaya ploschad") ia a square in the Tsentralny District of Saint Petersburg. In some guidebooks this square may be also named a "Riding-School Square": "riding school" is one of the variants in which and may be translated. The shape of Manezhnaya Square is close to the right-angled triangle. Its longest cathetus, the southern side of Manezhnaya Square is formed with "Italyanskaya Street", which runs parallel to Nevsky Prospect, at about hundred meters north of it. The shortest cathetus is "Karavannaya Street", which forms the eastern side of the square running from Nevky