How to calculate an angle from three points?

If you mean the angle that P1 is the vertex of then using the Law of Cosines should work:

arccos((P122 + P132 – P232) / (2 * P12 * P13))

where P12 is the length of the segment from P1 to P2, calculated by

sqrt((P1x – P2x)2 + (P1y – P2y)2)

Related Posts:

  1. How to determine if a point is in a 2D triangle?
  2. In a triangulated isometric grid, what triangle is a given point in?
  3. Is log(n!) = Θ(n·log(n))?
  4. Calculate distance between two latitude-longitude points? (Haversine formula)
  5. What is O(log* N)?
  6. What is the big-O of the function (log n)^k
  7. What is a loop invariant?
  8. What is a loop invariant?
  9. Unfamiliar symbol in algorithm: what does ∀ mean? [closed]
  10. What does O(log n) mean exactly?
  11. how to calculate binary search complexity
  12. When is it practical to use Depth-First Search (DFS) vs Breadth-First Search (BFS)? [closed]
  13. What does O(log n) mean exactly?
  14. What is Sliding Window Algorithm? Examples?
  15. Quicksort with Python
  16. What is the difference between tree depth and height?
  17. how to implement quick sort algorithm in C++
  18. Python: maximum recursion depth exceeded while calling a Python object
  19. Why is the time complexity of both DFS and BFS O( V + E )
  20. Time complexity of a Priority Queue in C++
  21. What is stability in sorting algorithms and why is it important?
  22. Breadth First Search time complexity analysis
  23. Counting the sum of every nodes’ neighbors’ degrees?
  24. Time Complexity of the Kruskal Algorithm?
  25. Quick Sort Vs Merge Sort
  26. Polynomial time and exponential time
  27. Insertion Sort vs. Selection Sort
  28. Difference and advantages between dijkstra & A star
  29. Best Case for Bubble Sort
  30. How to find the kth smallest element in the union of two sorted arrays?
  31. Big O, how do you calculate/approximate it?
  32. Performing Breadth First Search recursively
  33. Is Quicksort in-place or not?
  34. longest increasing subsequence(O(nlogn))
  35. O(n log n) vs O(n) — practical differences in time complexity
  36. When should I use Kruskal as opposed to Prim (and vice versa)?
  37. Trying to understand max heapify
  38. Shortest possible depth of a leaf in decision tree (comparison sorting algorithm)
  39. Python Weighted Random [duplicate]
  40. What is the meaning of “exclusive” and “inclusive” when describing number ranges?
  41. What’s a good algorithm to generate a maze?
  42. Intuition for perceptron weight update rule
  43. Easy: Solve T(n)=T(n-1)+n by Iteration Method
  44. What is tail call optimization?
  45. PacMan: what kinds of heuristics are mainly used?
  46. Quicksort vs heapsort
  47. Big-oh vs big-theta
  48. How can I check if two segments intersect?
  49. Best case time complexity for selection sort
  50. Looking for algorithm finding euler path
  51. Trie complexity and searching
  52. What does this definition of contiguous subsequences mean?
  53. Is complexity O(log(n)) equivalent to O(sqrt(n))?
  54. How to find maximum spanning tree?
  55. Exactly how many comparisons does merge sort make?
  56. Algorithm to return all combinations of k elements from n
  57. How to calculate big-theta
  58. What is the time complexity of while loops?
  59. Merge sort time and space complexity
  60. Intuitive explanation for why QuickSort is n log n?
  61. Shuffle a deck of cards in Java
  62. How to calculate time complexity of backtracking algorithm?
  63. Median of Medians in Java
  64. What is a loop invariant?
  65. Hash table runtime complexity (insert, search and delete)
  66. Which is better: O(n log n) or O(n^2)
  67. Quickselect time complexity explained
  68. What is the proper equivalent of “while(true)” in plain C?
  69. Bellman-Ford vs Dijkstra: Under what circumstances is Bellman-Ford better?
  70. Asymptotic Notation – does n (log n) (log n) simplify?
  71. Difference between Big-O and Little-O Notation
  72. Why is O(n) better than O( nlog(n) )?
  73. How to solve: T(n) = T(n/2) + T(n/4) + T(n/8) + (n)
  74. Is there an O(n) integer sorting algorithm?
  75. An example of Best Case Scenario for Quick Sort (Need someone to check if my answer is correct)
  76. how to write a recurrence relation for a given piece of code
  77. Why is merge sort worst case run time O (n log n)?
  78. Why is merge sort worst case run time O (n log n)?
  79. What is the time and space complexity of a breadth first and depth first tree traversal?
  80. Create your own MD5 collisions
  81. Image Segmentation using Mean Shift explained
  82. Finding the median of an unsorted array
  83. Difference between Big-Theta and Big O notation in simple language
  84. What is the difference between bucket sort and radix sort?
  85. How are the following functions O(N^3)?
  86. Difference between O(n) and O(log(n)) – which is better and what exactly is O(log(n))?
  87. Finding all possible combinations of numbers to reach a given sum
  88. Are there any real O(n^n) algorithms?
  89. Sorting an array in C?
  90. Finding square root without using sqrt function?
  91. Is Dijkstra’s algorithm for directed or undirected graphs?
  92. Modular multiplicative inverse function in Python
  93. Minesweeper solving algorithm
  94. About bubble sort vs merge sort
  95. What does the ^ (XOR) operator do? [duplicate]
  96. Clamping floating numbers in Python?
  97. Infinite integer in Python
  98. How to perform bilinear interpolation in Python
  99. What is the most efficient way to calculate the least common multiple of two integers?
  100. Rotating a Vector in 3D Space

Leave a Comment