The fact that such a triangle, square, cube, geometry is the science tells us.In today's world it is taught in schools without exception.Also, the science that studies directly that such a triangle, and what his property is trigonometry.It explores in detail all the events associated with these geometric shapes.The fact that such a triangle, and we'll talk today in our article.Below will be described types, as well as some of the theorems associated with them.
What triangle?Determination
It is a flat polygon.It has three angles, that is clear from its name.He also has three sides and three points, the first of them - it stretches, the second - the point.Knowing what are the two angles, you can find the third, subtracting the sum of the first two from the number 180.
What are triangles?
They can be classified according to various criteria.
First and foremost, they are divided into acute-angled, obtuse and rectangular.First they have sharp corners, i.e. those which are less than 90 degrees.In one corner of the obtuse - blunt, that is, one that is more than 90 degrees, the other two - sharp.It also includes an acute triangle and equilateral.Such triangles all sides and angles equal.All of them are equal to 60 degrees, it can easily be calculated by dividing the sum of all angles (180) by three.
right triangle
It is impossible not to talk about what a right triangle.
In one corner of the figure is 90 degrees (straight line), it has two of its sides are arranged perpendicular.The remaining two corners are sharp.They may be equal, then it is an isosceles triangle.With a right triangle is related Pythagorean theorem.Using it you can find a third party knowing the first two.According to this theorem, if we add the square of one leg to the other square, you can get a square of the hypotenuse.The square of the leg can be calculated by subtracting the square of the hypotenuse squared famous leg.Talking about what the triangle, you can remember about isosceles.This is such in which two of the sides are equal, and also equal to two angles.
What is a leg and hypotenuse?
Catete - this is one side of the triangle, which form an angle of 90 degrees.Hypotenuse - it remains a side that is opposite the right angle.Because of his leg, you can drop a perpendicular.The ratio of the adjacent side to the hypotenuse was referred to as the cosine, and the opposite - sine.
Egyptian triangle - what are its characteristics?
It is rectangular.His legs are equal to three and four, and the hypotenuse - five.If you saw the legs of this triangle are equal to three or four, you can be sure that the hypotenuse is equal to five.Also according to this principle can easily determine that the leg will be equal to three if the second is equal to four, and the hypotenuse - five.To prove this statement, you can use the Pythagorean theorem.If two equal leg 3 and 4, 9 + 16 = 25, the root 25 - is 5, that is the hypotenuse equals 5. Also Egyptian called rectangular triangle whose sides are equal to 6, 8 and 10;9, 12 and 15, and other numbers with the ratio 3: 4: 5.
What else can be a triangle?
triangles also can be entered and described.The figure around which describes a circle is called the inscribed, all of its vertices are the points lying on the circle.Described Triangle - one in which the inscribed circle.All of its side in contact with it at certain points.
How is the area of a triangle?
Area any shape is measured in square units (sq. Meters sq. Millimeters, sq. Centimeters sq. Decimeters and t. D.) This value can be calculated in various ways, depending on the type of a triangle.Area whatever shape with corners can be found if you multiply it on the side perpendicular dropped on it from the opposite angle, and dividing this figure by two.Also this value can be found by multiplying the two sides.Then multiply that number by the sine of the angle located between the parties, and it will get divided into two.Knowing all sides of the triangle, but without knowing its corners, the area can be found in another way.To do this, find the perimeter of the half.Then, one by one take away from the number of different directions and multiply received four values.Next, find the square root of the number that came out.The area of the inscribed triangle can be found by multiplying all sides and dividing that number by the radius of the circle described around him, multiplied by four.
area of the triangle is described as follows: half the perimeter multiplied by the radius of a circle that is inscribed in it.If an equilateral triangle, its area can be found as follows: side squaring, multiplying the resulting figure by the square root of three, then divide that number by four.Similarly, one can calculate the height of a triangle in which all sides are equal to that one of them must be multiplied by a root of three, and then divide this number by two.
theorems related to the triangle
basic theorems that relate to this figure are the Pythagorean theorem, described above, the theorem of sines and cosines.The second one (sine) is that if any side divided by the sine of the angle opposite to it, it is possible to obtain the radius of a circle described around multiplied by two.The third (cosine) is that if the sum of the squares of the two sides of the same product taken away, two and multiplied by the cosine of the angle situated between them, form a square third party.
Dali Triangle - what is it?
Many people, faced with this concept, at first thought it was some sort of definition in geometry, but it is not so.Dali Triangle - is the common name of three places that are closely connected with the life of the famous artist."Top" it is the house where Salvador Dali lived in the castle, which he gave to his wife, as well as the Museum of surrealist paintings.During a tour of these places you can learn many interesting facts about this kind of creative artist, famous around the world.
