A collection of functions for performing trigonometry in JavaScript.

trigonometry.coffee

# Requirement: https://gist.github.com/jgphilpott/092c0f3e1bcfa75f543e8485b9b23e7d

# In all triangles the sum of the angles is always equal to 180 degrees.
angle$angles = (a = null, b = null) ->

    if a + b < 180

        return 180 - a - b

    else

        return null

# Pythagorean Theorem is a^2 + b^2 = c^2 ... where 'c' is the hypotenuse.
side$sides = (a = null, b = null, c = null) ->

    if typeof a == "number" and typeof b == "number" and not c

        return Math.sqrt Math.pow(a, 2) + Math.pow(b, 2)

    else if typeof a == "number" and not b and typeof c == "number"

        return Math.sqrt Math.pow(c, 2) - Math.pow(a, 2)

    else if not a and typeof b == "number" and typeof c == "number"

        return Math.sqrt Math.pow(c, 2) - Math.pow(b, 2)

    else

        return null

# Remember: SOH-CAH-TOA
angle$sides = (hypotenuse = null, adjacent = null, opposite = null) ->

    if typeof hypotenuse == "number" and not adjacent and typeof opposite == "number"

        return rad$deg Math.asin opposite / hypotenuse

    else if typeof hypotenuse == "number" and typeof adjacent == "number" and not opposite

        return rad$deg Math.acos adjacent / hypotenuse

    else if not hypotenuse and typeof adjacent == "number" and typeof opposite == "number"

        return rad$deg Math.atan opposite / adjacent

    else

        return null

# Remember: SOH-CAH-TOA
side$angle = (angle = null, hypotenuse = null, adjacent = null, opposite = null) ->

    if typeof angle == "number" and angle < 180

        if typeof hypotenuse == "number"

            if adjacent

                return hypotenuse * Math.cos deg$rad angle

            else if opposite

                return hypotenuse * Math.sin deg$rad angle

            else

                return null

        else if typeof adjacent == "number"

            if hypotenuse

                return adjacent / Math.cos deg$rad angle

            else if opposite

                return adjacent * Math.tan deg$rad angle

            else

                return null

        else if typeof opposite == "number"

            if hypotenuse

                return opposite / Math.sin deg$rad angle

            else if adjacent

                return opposite / Math.tan deg$rad angle

            else

                return null

        else

            return null

    else

        return null

trigonometry.js

// Generated by CoffeeScript 2.7.0
// Requirement: https://gist.github.com/jgphilpott/092c0f3e1bcfa75f543e8485b9b23e7d

var angle$angles, angle$sides, side$angle, side$sides;

// In all triangles the sum of the angles is always equal to 180 degrees.
angle$angles = function(a = null, b = null) {
  if (a + b < 180) {
    return 180 - a - b;
  } else {
    return null;
  }
};

// Pythagorean Theorem is a^2 + b^2 = c^2 ... where 'c' is the hypotenuse.
side$sides = function(a = null, b = null, c = null) {
  if (typeof a === "number" && typeof b === "number" && !c) {
    return Math.sqrt(Math.pow(a, 2) + Math.pow(b, 2));
  } else if (typeof a === "number" && !b && typeof c === "number") {
    return Math.sqrt(Math.pow(c, 2) - Math.pow(a, 2));
  } else if (!a && typeof b === "number" && typeof c === "number") {
    return Math.sqrt(Math.pow(c, 2) - Math.pow(b, 2));
  } else {
    return null;
  }
};

// Remember: SOH-CAH-TOA
angle$sides = function(hypotenuse = null, adjacent = null, opposite = null) {
  if (typeof hypotenuse === "number" && !adjacent && typeof opposite === "number") {
    return rad$deg(Math.asin(opposite / hypotenuse));
  } else if (typeof hypotenuse === "number" && typeof adjacent === "number" && !opposite) {
    return rad$deg(Math.acos(adjacent / hypotenuse));
  } else if (!hypotenuse && typeof adjacent === "number" && typeof opposite === "number") {
    return rad$deg(Math.atan(opposite / adjacent));
  } else {
    return null;
  }
};

// Remember: SOH-CAH-TOA
side$angle = function(angle = null, hypotenuse = null, adjacent = null, opposite = null) {
  if (typeof angle === "number" && angle < 180) {
    if (typeof hypotenuse === "number") {
      if (adjacent) {
        return hypotenuse * Math.cos(deg$rad(angle));
      } else if (opposite) {
        return hypotenuse * Math.sin(deg$rad(angle));
      } else {
        return null;
      }
    } else if (typeof adjacent === "number") {
      if (hypotenuse) {
        return adjacent / Math.cos(deg$rad(angle));
      } else if (opposite) {
        return adjacent * Math.tan(deg$rad(angle));
      } else {
        return null;
      }
    } else if (typeof opposite === "number") {
      if (hypotenuse) {
        return opposite / Math.sin(deg$rad(angle));
      } else if (adjacent) {
        return opposite / Math.tan(deg$rad(angle));
      } else {
        return null;
      }
    } else {
      return null;
    }
  } else {
    return null;
  }
};