### atan2

#### Determine the coordinates of a segment

How can I use atan2 to determine the coordinates where a segment ends, knowing the coordinates where it starts (x, y), the angle of the segment and the length of the segment? Can you tell me a solution it doesn't have to be only with atan2...

You have a right angled triangle and you can assume that the point A is at (x,y), this is much easier to explain with the use of some diagrams: Now we know what the value for c is already because this is the length of the segment and we want to know the values for a and b because the final point is at (x+b, y+a) From trigonometry we know what the relations between the angles and the ratios of the sides are sin(theta) = opposite/hypotenuse and cos(theta) = adjacent/hypotenuse Substituting in the values we know we get: sin(theta) = opposite/c c = opposite * sin(theta) and cos(theta) = adjacent/b b = adjacent * cos(theta) We know that the end point is at (x+b, y+a) which given the values for the edges we found is (x+adjacent * cos(theta), y+opposite * sin(theta))

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Determine the coordinates of a segment

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