Equilateral triangle terms of side length "a" can be derived directly using the Pythagorean theorem or using trigonometry. The area of a triangle is half of one side "a" times the height "h" from that side: The legs of either right triangle formed by an altitude of the equilateral triangle are half of the base "a", and the hypotenuse is the side "a" of the equilateral triangle. The height of an equilateral triangle can be found using the Pythagorean theorem so that Substituting "h" into the area formula (1/2)"ah" gives the area formula for the equilateral triangle: Using trigonometry, the area of
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