Relationship between circle angle and circle center angle There is a chord in a circle with radius 1. If its length is root 3, then the degree of the circle angle to which the chord is opposite is equal to ()

Using Pythagorean theorem to get the chord center distance of 1 / 2, then we can find that the center angle of the string pair is 120 degrees
The answer to the 120 degree circle is 60 degrees

The relation theorem of circle angle and circle center angle? Two of them are the circumference angle and the center angle It's better to write geometric expressions,

1. In the same circle or equal circle, the circle angles opposite to the same arc or equal arc are equal. They are equal to half of the central angle of the circle to which the arc is opposite; the arcs to which the equal circular angles are opposite are equal
2. The circle angle of an arc is equal to half of the center angle of the circle it is opposite

The relationship between the center angle and the circumference angle?

The circumference angle is equal to 1 / 2 of the center angle
The center angle is equal to twice the circumference angle

Center angle and circumference angle In addition, please give an example. If you take a circle as the vertex, can the angle formed by two radii pass through the circle center angle? Brothers and sisters, And What is the relationship between the circumference angle and the center angle under what circumstances,

The center angle is the angle of the vertex on the center of the circle
You are right
Of course, they should be on the other two corners of the circle
The center angle of the other two points at the same position of the circle is twice of the circumference angle

How to infer the relationship between the circumference angle and the center angle

Draw any central angle of a circle, then draw his circumference angle, connect the points on the circle with the center of the circle, and then prove it according to the supplementary intersection of 180 degrees

How to prove that the circumference angle is half of the center angle? Please prove ∠ 1 = 2 ∠ 2. Don't tell me that the circle angle of the same arc is half of the center angle. I want the reason

Record the diameter as CD
OC=OA,∠AOD=2∠ACO (1)
OB=OC,∠BOD=2∠BCO (2)
(1) (2) obtained
∠2=2(∠ACO-∠BCO)=2∠1

Given that the area of an equilateral triangle is 6 times the root sign 3, then the area of the ring formed by its inscribed circle and circumscribed circle is Please elaborate. Thank you

Simple:
According to the sine theorem area s = (a × B × sinc) △ 2, it is immediately known that the side length of the triangle is 2 √ 6. According to the definition of internal and external tangent, it is easy to know that r = 2 √ 2, r = √ 2, so the area of the ring is Π (8-2), that is, the result is 6 Π

Given that the radius of circumscribed circle and inscribed circle of a regular n-polygon are 20cm and 3cm respectively, the side length and area of the regular polygon are calculated

By using Pythagorean theorem, it is obtained that half of the side length of the regular polygon = root (square of 20 - (square of 10 root sign 3)) = 10, side length of regular polygon = 10 * 2 = 20, at the same time, 10 divided by 20 = 1 / 2, the angle between the radius of inscribed circle and the radius of adjacent circumscribed circle is 30 degrees, the radius of two adjacent circumscribed circles is 30 * 2 = 60 degrees, 360 degrees / 60 degrees = 6

What are the radius formulas of inscribed circle and circumscribed circle of square and triangle respectively? Just like the formula of the radius of the inscribed circle of the RT triangle is r = C / 2 (C is the hypotenuse) The circumcircle radius is r = a + B-C / 2 Radius formula of inscribed circle and circumscribed circle of square and ordinary triangle

If the side length of the square is a, then the radius of the inscribed circle is a / 2, and the radius of the circumscribed circle is √ 2A / 2. If the three sides of an ordinary triangle triangle are: A.B.C, then the angles corresponding to their sides are: angle A. angle B. angle C. then the radius of inscribed circle r = a * b * sinc / (a + B + C) = b * c * Sina / (a + B + C) = C * a * SINB / (a + B + C) if there is no angle A. angle B. angle c

Radius formula of circumscribed circle and inscribed circle of regular tetrahedron

The inscribed circle is 1 / 4 high and the circumscribed circle is 3 / 4 high
Inscribed circle algorithm: using equal volume formula: tetrahedron (s, H) can be replaced by four equal volume triangular cones (s, H)
4 * 1 / 3 * sh = 1 / 3SH, H = 1 / 4H

Relationship between circle angle and circle center angle There is a chord in a circle with radius 1. If its length is root 3, then the degree of the circle angle to which the chord is opposite is equal to ()