A circle has area = 4

Calculate Area, Circumference, Radius, Diameter

Calculate radius (r):

A = πr2

Rearranging the equation, we get:

r2  =  A
  π

r  =  √A
  √π

r  =  √4
  √3.1415926535898

r  =  2
  1.7724538509055

r = 1.1283791670955

Calculate circumference (C):

C = 2πr

C = 2π * 1.1283791670955

C = 2.2568π or 7.0898

Calculate diameter (d):

d = 2r

d = 2 * 1.1283791670955

d = 2.256758334191

Final Answers


r = 1.1283791670955
C = 2.2568π or 7.0898
d = 2.256758334191


Download the mobile appGenerate a practice problemGenerate a quiz
Common Core State Standards In This Lesson
7.G.B.4
What is the Answer?
r = 1.1283791670955
C = 2.2568π or 7.0898
d = 2.256758334191
How does the Circles Calculator work?
Free Circles Calculator - Calculates and solves for Radius, Diameter, Circumference, and Area of a Circle.
This calculator has 1 input.
What 3 formulas are used for the Circles Calculator?
d=2r
A = 2πr2
C=2πr
What 7 concepts are covered in the Circles Calculator?
area
Number of square units covering the shape
circle
the set of all points in the plane that are a fixed distance from a fixed point
circles
circumference
the perimeter of a circle or ellips
diameter
distance from two endpoints of a circle through the center
d = 2r
origin
On a two digit coordinate plane, the point (0, 0), where the x-axis and y-axis cross.
radius
Distance from the center of a circle to the edge
C/2π
Example calculations for the Circles Calculator
  1. Circle radius = 2
  2. Circle diameter = 2
  3. Circle area = 2
  4. Circle circumference = 2
  5. Circle radius = 3
  6. Circle diameter = 3
  7. Circle area = 3
  8. Circle circumference = 3
  9. Circle radius = 4
  10. Circle diameter = 4
  11. Circle area = 4
  12. Circle circumference = 4
  13. Circle radius = 5
  14. Circle diameter = 5
  15. Circle area = 5
  16. Circle circumference = 5
  17. Circle radius = 6
  18. Circle diameter = 6
  19. Circle area = 6
  20. Circle circumference = 6
  21. Circle radius = 7
  22. Circle diameter = 7
  23. Circle area = 7
  24. Circle circumference = 7
  25. Circle radius = 8
  26. Circle diameter = 8
  27. Circle area = 8
  28. Circle circumference = 8
  29. Circle radius = 9
  30. Circle diameter = 9
  31. Circle area = 9
  32. Circle circumference = 9
  33. Circle radius = 10
  34. Circle diameter = 10
  35. Circle area = 10
  36. Circle circumference = 10
  37. Circle radius = 11
  38. Circle diameter = 11
  39. Circle area = 11
  40. Circle circumference = 11
  41. Circle radius = 12
  42. Circle diameter = 12
  43. Circle area = 12
  44. Circle circumference = 12
  45. Circle radius = 13
  46. Circle diameter = 13
  47. Circle area = 13
  48. Circle circumference = 13
  49. Circle radius = 14
  50. Circle diameter = 14
  51. Circle area = 14
  52. Circle circumference = 14
  53. Circle radius = 15
  54. Circle diameter = 15
  55. Circle area = 15
  56. Circle circumference = 15
  57. Circle radius = 16
  58. Circle diameter = 16
  59. Circle area = 16
  60. Circle circumference = 16
  61. Circle radius = 17
  62. Circle diameter = 17
  63. Circle area = 17
  64. Circle circumference = 17
  65. Circle radius = 18
  66. Circle diameter = 18
  67. Circle area = 18
  68. Circle circumference = 18
  69. Circle radius = 19
  70. Circle diameter = 19
  71. Circle area = 19
  72. Circle circumference = 19
  73. Circle radius = 20
  74. Circle diameter = 20
  75. Circle area = 20
  76. Circle circumference = 20
Circles Calculator Video

Tags:



Add This Calculator To Your Website




An Automated Online Math Tutor serving 8.1 million parents and students in 235 countries and territories.

Our Services
Top Categories
Community