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A right triangle is a geometric figure with a right angle. There are two kinds of right-angled triangles: ordinary right-angled triangles and isosceles right-angled triangles. It conforms to Pythagorean theorem and has some special properties and judgment methods.
Right-angled triangles are shown in figure 1: there are two cases, namely, ordinary right-angled triangles and isosceles right-angled triangles (special cases). In a right triangle, two sides adjacent to the right angle are called right angles, and the opposite side of the right angle is called hypotenuse.
The right angle of a right triangle is also called a "chord". If the lengths of two right-angled sides are not equal, the short side is called "hook" and the long side is called "strand".
An isosceles right triangle is a special triangle, which has all the properties of a triangle: stability, and the sum of internal angles is 180. The two right angles are equal and the two acute angles are 45 degrees. The midline, bisector and vertical line on the hypotenuse of the isosceles right triangle are unified, and the height on the hypotenuse of the isosceles right triangle is the radius r of the circumscribed circle of the triangle.
If the two right angles of a right triangle are A and B and the hypotenuse is C, then A 2+B 2 = C 2; That is to say, the sum of squares of the lengths of two right angles of a right triangle is equal to the square of the length of the hypotenuse. If three sides A, B and C of a triangle satisfy A 2+B 2 = C 2. Call quickly.
One right-angled side is A and the other right-angled side is B. If the sum of squares of A and B is equal to the square of hypotenuse C, then this triangle is a right-angled triangle. (called the inverse theorem of Pythagoras theorem) was put forward by Pythagoras in 550 BC.
Generally speaking, a right triangle has five elements besides a right angle, namely three sides and two acute angles. The process of finding unknown elements other than right angles from known elements is called solving right triangles.
Abstract practical problems into mathematical problems (draw a plane figure and turn it into solving right triangle problems). According to the characteristics of conditions, the acute triangle function is properly selected to solve the right triangle; Get the answer to this math problem.