![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
If the area of a sector with a radius of 16 cm is equal to that of a circle with a radius of 8 cm, then the arc length of this sector is () with π reserved
Let the arc length be xcm,
(1/2)×16x=π8^2
The solution is x = 8 π
So the arc length of this sector is 8 π cm
The central angle of a fan-shaped circle is 60 degrees. The arc length of the central angle is 3.14 cm. What is the area of this sector? Clear and clear,
3.14 △ 60 / 360 = 18.84cm (i.e. the circumference of the whole circle)
18.84 △ 2 △ 3.14 = 3cm (radius of circle)
The fan area is: 3.14 x 3 x 3 x 60 / 360 = 4.71 square centimeters
Answer: 4.71 square centimeter
That's enough. Give me a score (^_ ^)
Note: 60 / 360 is a fraction, "/" is not a divisor, it is a fractional line
The radius of the sector is 2 cm and the center angle is 60 ° so what is the area of the sector?
2 × 2 × 3.14 × 60 △ 360 = 2.093 (square centimeter)
The circumference of fan-shaped AOB is 8 cm (1) If the area of the sector is 3cm2, find the size of the central angle of the circle; (2) Find the area of the sector and get the maximum value of the center angle and chord length ab
Let the radius of the sector AOB be r, the arc length L, and the center angle of the circle α (1). From the problem 2R + L = 812lr = 3, the solution is: r = 3L = 2 or r = 1L = 6
A fan with a center angle of 45 ° and a radius of 8 cm has a circumference of () cm
According to the formula of arc length: arc length of sector = (45 × π × 8) / 180 = 2 π
So perimeter = 8 + 8 + 2 π = 16 + 2 π
If the perimeter of the sector is 8cm and the area is 4cm2, then the radian number of the central angle of the sector is () A. 1 B. 3 Two C. 2 D. 3
Let the arc length of the sector be l and the radius r, so 2R + L = 8,1
2lr＝4，
So l = 4, r = 2,
So the number of radians of the central angle of the sector is 4
2＝2；
Therefore, C
It is known that the circumference of the sector AOB is 8 cm. (1) if the area of the sector is 3 square cm, find the size of its central angle
Let the radius be x and the arc length y
Then 2x + y = 8 (1)
1/2xy=3(2)
The solution is: x = 1, y = 6 or x = 3, y = 2
When x = 1, y = 6, because n π * 1 / 180 = 6, n = 1080 / π
When x = 3, y = 2, because n π * 3 / 180 = 2, n = 120 / π
That is, the center angle of the circle is 1080 / π or 120 / π degree
Hope to adopt!
If the perimeter of the sector is 8cm and the area is 4cm2, then the radian number of the central angle of the sector is () A. 1 B. 3 Two C. 2 D. 3
Let the arc length of the sector be l and the radius r, so 2R + L = 8,1
2lr＝4，
So l = 4, r = 2,
So the number of radians of the central angle of the sector is 4
2＝2；
Therefore, C
If the perimeter of the sector is 8cm and the area is 4cm2, then the radian number of the central angle of the sector is () A. 1 B. 3 Two C. 2 D. 3
Let the arc length of the sector be l and the radius r, so 2R + L = 8,1
2lr＝4，
So l = 4, r = 2,
So the number of radians of the central angle of the sector is 4
2＝2；
Therefore, C
Given that the circumference of the sector is 6cm and the area is 2cm, the arc degree of the center angle of the fan is Hurry! Get the right answer!
Let the center angle of the sector be a and the radius of the sector be r
Then: S = pi * R ^ 2 * A / (2 * PI) = a * R ^ 2 / 2 = 2
Perimeter = 2 * pi * r * A / (2 * PI) + 2 * r = R * a + 2 * r = 6
A*R^2/2=2
A*R+2*R=6
R*(A+2)=6
R=6/(A+2)
A*R^2/2=A*(6/(A+2))^2/2=2
18*A=2*(A+2)^2=2*(A^2+4*A+4)
9*A=A^2+4*A+4
A^2-5*A+4=0
(A-4)(A-1)=0
A = 1 radian or a = 4 radians
R = 6 / (a + 2) = 2cm or r = 6 / (a + 2) = 1cm
RELATED INFORMATIONS
- 1. It is known that the circumference of a sector is 8 cm and the area is 4 cm 2. Find the radian of the central angle of the circle
- 2. Given its chord length of 2360 mm and arch height of 600mm, the best formula to find the arc length is! Given its chord length of 1760mm and arch height of 600mm, how much is the arc length!
- 3. Knowing that the chord length is the same as the arc length, how to calculate the diameter
- 4. Given that the radius of the ball is 2, the two perpendicular planes cut off the spherical surface respectively to obtain two circles. If the common chord length of the two circles is 2, the distance between the centers of the two circles is equal to___ .
- 5. The radius of the circle where an arc is located is 60 cm, and the angle of the center of the circle where the arc is located is 80 degrees. What fraction of the circumference of the circle is occupied by this arc? Write the process and the answer, to speed oh
- 6. Arc AB = arc a'b'what does it mean? Are the two arcs equal or are they of equal length?
- 7. Given that the radius of circle O is R and the length of chord AB is also R, find the degree of ∠ AOB The title is like the title. The red flag is yours
- 8. As shown in the figure, the known point O is a point on the inclined edge AC of RT △ ABC, and ⊙ o with point o as the center of the circle and the length of OA as the radius is tangent to point E, intersect with AC at point D, and connect AE (1) Verification: AE bisection ∠ cab; (2) This paper explores the quantitative relationship between ∠ 1 and ∠ C, and finds the value of Tanc when AE = EC
- 9. As shown in the figure, three straight lines AB, CD and EF intersect at the same point O, if ∠ AOE = 2 ∠ AOC, ∠ COF = 3 2 ∠ AOE, then ∠ doe=______ .
- 10. If the radius of the circle becomes 3 times of the original one, and the arc length remains unchanged, the angle of the arc to the center of the circle is several times that of the original arc
- 11. Given that the center angle of the circle is 60 degrees and the arc length is 2 π cm, what is the radius length of the sector? With publicity, specific
- 12. If the number of radians of the center angle of a fan-shaped circle is 2 and the chord length of the sector arc is 2, then the area of the sector is () A. 1 sin21 B. 2 sin22 C. 1 cos21 D. 2 cos22
- 13. Given the arc length and arc height, calculate the arc diameter? Arc length 2240mm, radian height 500mm. Please inform the formula and results
- 14. If the area of the sector with a 72 ° central angle is 628 square centimeters, the area of the circle to which the sector is directed is () square centimeter
- 15. If the arc length of a sector is 20 π cm and the area is 240 π cm 3, what is the central angle of the sector? Who can explain it clearly,
- 16. When the radius is 4 In the circle of π, the arc length corresponding to the center angle of 45 ° is equal to______ .
- 17. If the radius of the circle is 50cm, then the circumference of the arc corresponding to the central angle of 30 ° is______ .
- 18. If the length of an arc is 18.84cm, and the radius of this arc is 4cm, what degree is the central angle of the arc
- 19. In a circle with a radius of 6cm, there is a sector. The arc length corresponding to the central angle of the sector is 6.28cm. What is the area of the sector?
- 20. If the arc length of the fan is 20cm and the radius is 5cm, then its area is______ cm2．