How to calculate the angle of a right triangle and what is the formula for calculating the angle of

Use the Pythagorean theorem b 2 = c 2-a 2 to find the length of b and then use the sine theorem.

b (sinb) = c (sin90) to get the value of sinb, and finally get sinb = ((c 2-a 2) open root number) c, you can find the required value.

Right triangles are divided into two cases, there are ordinary right triangles, and isosceles right triangles (special cases) In right triangles, the two sides adjacent to the right angles are called right angles, and the sides opposite the right angles are called hypotenuses. The sides of a right triangle are also called "chords". If the two right-angled sides are not the same length, the short side is called the "hook" and the long side is called the "strand".

An isosceles right triangle is a special type of triangle that has the properties of all triangles: with stability, an internal angle sum of 180 °. The two right-angled sides are equal, the two acute angles are 45°, and the hypotenuse is on the midline and the angle bisector.

Perpendicular line three in one.

The height on the hypotenuse of an isosceles right triangle is the circumscribed circle of this triangle.

radius r.

The length of the two sides is 10mm

Is 220mm a hypotenuse? Let c be a right angle, sinb = 10 220 = and look up the trigonometric table to get the degree of b, a = 90°-b. This gives you two corners.

This is who came up with the question.

It doesn't make sense. I can't count the pen.

Use a calculator.

Let me tell you how.

I don't know if you've learned.

Let's just talk about the first one.

Let the desired angle be a

tan（a）=9/40

Use a calculator to calculate a=arctan(9 40)=The second question is.

are all approximately equal to.

All I can say is that the 2nd floor has never read a nursery class

It's hard to give you a satisfactory answer to this sentence, right triangle.

Know that two right-angled edges are angled with a tangent or cotangent function.

Know that one of the right-angled edges calculates the angle using a sine or cosine function.

Among them, you need to know how to look up the trigonometric function table.

The length of the three sides of a right triangle is known, and their angles can be calculated using the hypotenuse formula.

Among the six elements of the right-angled triangle ABC, except for the right-angled C, the remaining five elements have the following relationship:

a+∠b=90°

sina = ( a) opposite edge hypotenuse.

cosa=(a) adjacent edge hypotenuse.

tana = ( a) opposite edge adjacent to the edge.

For example, if the opposite side of a is 4 meters and the hypotenuse c is 8 meters, how many degrees is the calculation of angle a?

According to sina = ( a) opposite side hypotenuse, 4 8 =, look up the table sin30 ° =, and get the angle a is equal to 30 °.

1) Two acute angles of a right-angled triangle are interconnected; (2) The middle line on the hypotenuse of a right triangle is equal to half of the hypotenuse; (3) In a right-angled triangle, if there is an acute angle equal to 30°, then the right-angled side it is opposite is equal to half of the hypotenuse; (4) In a right-angled triangle, if a right-angled side is equal to half of the hypotenuse, then the acute angle of the right-angled side is equal to 30°; (5) In a right-angled triangle, the sum of the squares of the two right-angled sides A and B is equal to the square of the hypotenuse c, i.e., A2 B2=C2(Pythagorean theorem); (6) (h is the height on the hypotenuse), the middle line on the hypotenuse of the circumscribed circle radius, and the inscribed circle radius.

If the right triangle ABC and c are right angles, the opposite sides of a and b are a and b respectively. Using trigonometric relations, there are sin a=a c, sin b=b c. The inverse trigonometric function is then used to obtain a=arcsin(a c).

The most commonly used formulas for right triangles are 1 Pythagorean theorem: b 2=c 2-a 22 and sine theorem: b (sinb) = c (sin90).

The rest is the multiplication of two right-angled sides of a triangle equal to one-half the area.

1) Two acute angles of a right-angled triangle are interconnected; (2) The middle line on the hypotenuse of a right triangle is equal to half of the hypotenuse; (3) In a right-angled triangle, if there is an acute angle equal to 30°, then the right-angled side it is opposite is equal to half of the hypotenuse; (4) In a right-angled triangle, if a right-angled side is equal to half of the hypotenuse, then the acute angle of the right-angled side is equal to 30°; (5) h is the height on the hypotenuse), the middle line on the hypotenuse of the circumscribed circle radius, and the inscribed circle radius.

This is relatively complete.,I hope it can help you.,If you're satisfied, give a thumbs up.

The base of the triangle is multiplied by the height divided by two.

Right-angled triangle.

What is the formula for calculating angles? "Right Triangle" has told that one of the corners of this triangle is a right angle (90°), because the sum of the inner angles of the triangle is 180°, so the sum of the degrees of the remaining two angles is (180°-90°) 90°, that is, the remaining two angles of Lu Xiao must be acute angles. In a right-angled triangle, the ratio of the length of the right-angled side of an acute angle, the adjacent right-angled edge, and the hypotenuse is determined by the determination of the number of acute angles.

Conversely, as long as you know the length of any two of the three sides of a right triangle, you can use their ratio to find the degree of one of the acute angles, and then the length of the other acute angle and the other side. The ratio of special acute angles (30°, 45°, 60°) and right angles (90°) in a right triangle is easy to use using the Pythagorean theorem.

so usually the ratio of these special angles must be kept in mind. It is not easy to find the ratio of three sides of the general acute angle, so the relationship between the angle of the general acute angle and the ratio of the side length is usually obtained by looking up the table (trigonometric table or inverse trigonometric function.

table). The ratio of two pairs in a right-angled triangle is called a trigonometric function in a plane Cartesian coordinate system.

, take the origin O as the center of the circle, draw a circle with the radius of the long r, take a little tan lead p on the circle, the distance from the point p to the y axis is x, the distance to the x axis is y, even op = r, and the angle between the line segment op and the x axis is . Then: hypotenuse = r, opposite edge = y, adjacent edge = x, x r is called the sine value of , denoted by sin = x y; y r is called the cosine of .

value, with cos = y r; x y is called tangent.

Trigonometric functions with tan = y x for a few special angles:

sin30°=cos60°=1/2

cos30°=sin60°=√3/2

tan30° = 3 Let Si Hao 3

tan60°=√3

sin45°=cos45°=√2/2

tan45°=1

sin90°=1

cos90°=0

tan90° does not exist.

The angle is 90°; 37°，53°。

From 3+4=5, it can be seen that the triangle with side length 345 is a right-angled triangle, 3 and 4 are two right-angled sides, 5 is the hypotenuse, the opposite angle of the hypotenuse is a right angle, that is, 90°, the opposite angle of side length 3 is 37°, and the opposite side of side length 4 is 53°.

The process is as follows:

Because 3 2 + 4 2 = 5 2, it is a right triangle with a side length of 5 corresponding to an angle of 90°.

If the sine of the corresponding acute angle of the side length of 3 is 3 5, then its angle is arcsin3 5.

In the same way, the corresponding acute angle of the side length of 4 is arcsin4 5.

arcsin3/5≈，arcsin4/5≈

Judgment method: 1. Acute triangle: The three inner angles of the triangle are less than 90 degrees.

2. Right triangle: one of the three inner angles of the three-dimensional angle is equal to 90 degrees, which can be recorded as imitation RT.

3. Obtuse triangle: One of the three inner angles of the triangle is greater than 90 degrees.

A triangle with side lengths of 3,4,5 satisfies the inverse Pythagorean theorem, i.e., 3+4=5, then the triangle is a right-angled triangle. The inverse theorem of the Pythagorean theorem is a simple way to tell if a triangle is acute, right, or obtuse. If c is the longest side and a+b=c, then abc is a right triangle.