The formula for calculating the central angle of the circle in relation to the fan

Formula. Scalloped central corners.

n=(180l) (r)(degree).

where n is the number of angles at the center of the circle, and l is the arc length.

r is the radius. L(arc length) = (r 180) x x n The central angle of the circle refers to the AOB formed by the radius at both ends of the arc AB in a circle with the center of O, which is called the central angle of the arc AB. The central angle of the circle is equal to the circumferential angle of the same arc.

twice as much. The degree of the central angle of the circle is equal to the degree of the arc it opposes.

Relationship with arcs, chords, chord centrax.

In the same circle or equal circle, if one set of quantities is equal in the central distance of two circles, two arcs, two strings, and two chords, the corresponding other groups of quantities are also equal.

Equal arc to equal circle center angle. When dividing the vertex into 360 parts at the circumference of the center of the circle, the angle of the center of each part is 1°. Since the arcs of the central angles of the circle that are equal in the same circle are equal, the whole circle is also divided into 360 parts, and the arc obtained by each part is called an arc of 1°.

The formula for the central angle of a sector is: a=l r

a represents the radian of the central angle of the fan, l represents the length of the arc of the fan, and r represents the radius of the fan) n=180l pier

n represents the number of angles of the central angle of the fan, l represents the length of the arc of the fan, pie represents pi, and r represents the radius of the fan).

The circumference of the circle = 2 r

The arc is a part of the circle, therefore.

Arc length = circumference of the circle * (number of angles of the center of the circle to which the arc is opposed) 2 r * center angle of 360°

Because 2 = 360°

So. Sector centric angle = arc length radius.

The obtained unit is the number of radians, which should be replaced by the number of angles.

The formula for the number of angles in the center of a fan: n=(180l) (r)(degrees). The central angle refers to the AOB formed by the radii at both ends of the arc AB in a circle with the center of O, which is called the central angle of the arc AB.

The central angle is equal to twice the circumferential angle of the same arc.

The shape enclosed by an arc and two radii passing through both ends of the arc is called a fan (the combination of a semicircle and a diameter is also a fan). Obviously, it is made up of a part of the circumference of the circle and its corresponding central angle. The definition of the fan in the Geometry is as follows:

A figure enclosed by two sides of the corner where the vertex is at the center of the circle and a section of the arc that is truncated on both sides.

The nature of the central angle.

The vertex is the center of the circle.

Both sides intersect the circumference.

Properties of the central angle: In the same circle or equal circle, the arcs of the opposite central angles are equal, the opposite strings are equal, and the chord centroid distance of the opposite strings is also equal. In the same circle or equal circle, as long as one of the four pairs of quantities is equal, the other three pairs must be equal.

The degree of an arc is equal to the degree of the central angle of the circle to which it is opposed.

The circumferential angle of the semicircle (or diameter) is a right angle; The chord to which the circumferential angle of 90° is aligned is the diameter.

Summary. The central angle of the sector is n=(180l) (r)(degrees). where n is the number of angles at the center of the circle, l is the arc length, and r is the radius.

L(arc length) = (r 180) x x n The central angle of the circle refers to the AOB formed by the radius at both ends of the arc AB in a circle with the center of O, which is called the central angle of the arc AB. The central angle is equal to twice the circumferential angle of the same arc. The degree of the central angle of the circle is equal to the degree of the arc it opposes.

The central angle of the sector is n=(180l) (r)(degrees). where n is the number of angles at the center of the circle, l is the arc length, and r is the radius. L(arc length) = (r 180) x x n The central angle of the circle refers to the AOB formed by the radius at both ends of the arc AB in a circle with the center of O, which is called the central angle of the arc AB.

The central angle of the circle is equal to twice the circumferential angle of the same perturbation arc. The degree of the central angle of the circle is equal to the degree of the arc to which it is opposed.

I don't know how to find the center angle of the lone long.

Sector Area The area of the circle = the central angle of the circle 360°, so the central angle of the circle = 360° The area of the sector The area of the circle is the inversion of the formula. The radius of the sector and the length of the arc are known = l r (l is the arc length and r is the radius). Sector Area The area of the circle = the central angle of the circle 360°, so the central angle of the circle = 360° The area of the sector The area of the circle is the inversion of the formula.

The circumference of the circle = 2 r The arc is a part of the circle, so the arc length = the circumference of the circle (the number of angles of the circle to which the arc is centered is 360°) 2 r The central angle of the circle is 360° because 2 = 360°, so the center of the fan-shaped circle lacks a large tung angle = arc length radius. The obtained unit is the degree of arc imitation, which should be replaced by the number of angles.

Sector area formula.

Set the central corner. is a, the radius is r, and the circumferential ridge shedding rate.

is pi, when a is the angle of the feast s=a 360*pi*r 2;When a is a radian, s=1 2*a*r 2, the fan is an important figure related to the circle of cherry blossoms, and its area is related to the central angle (top angle) and the radius of the circle, and the area of the fan with the central angle of n° and the radius of r is n 360° r 2. If its apex angle is in radian units, it can be simplified to 1 2 arc length radius.

Let the radius of the bottom surface of the cone be r, the length of the bus bar is l, the arc length of the fan is 2 r, and the circumference of the circle with l as the radius is 2 l, then the arc length accounts for r l of the circumference of the entire front circle of the belt, the central angle of the circle accounts for r l of 360°, and the formula of the central angle is 360°*r l.

Or. s=n r 2 360=1 2rl (where r is the conical busbar, that is, the radius of the side view, l is the arc length of the side view, and n is the number of angles of the fan center).

l = 2 r (r is the radius of the bottom surface of the cone).

s=nπr^2/360=1/2r*2πr

Simplified: n=r r*360

The circumference of the circle = 2 r

The arc is part of the round stall, therefore.

Arc length. The circumference of the circle* (the angle of the center of the circle to which the arc is opposed.)

power 360°).

2 r*, the center of the circle is made at an angle of 360°

Because 2 = 360°

So the fan-shaped central angle = arc length radius.

The resulting unit is the number of radians of the line of lead, which should be replaced by the number of angles.

Sector Perimeter Formula Because the fan perimeter = radius 2 + one long and one short two arc lengths If the radius is r and the diameter is d, the degree of the central angle of the circle opposite by the fan is n°, then the fan perimeter:

c = 2r + (n 360) d = 2r + (n 180) r The arc length formula of this segment of the fan.

Angle system calculations.

l=n 360 2 r=n r 180, l is the arc length, n is the central angle of the fan, is the pi, and r is the radius of the base circle.

Radian system calculations.

l=|r , l is the arc length, |is the absolute value of the radians of the central angle to which the arc l is opposed, and r is the radius of the base circle.

The formula for the sector area in this paragraph.

r is the radius of the fan, n is the number of angles of the arc to the center of the circle, is the pi, and can also be divided by the area of the circle where the fan is located by 360 and multiplied by the angle of the central angle of the sector ns=n r 2 360

s=1/2lr

l is the arc length, r is the radius).

s=1/2|α|r^2