Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

I know the coordinates of one point on a circle, this point is part of a sector. I know the angle of the sector at the centre of radius, I know the radius and I know the arc length. How do I calculate the coordinates of the other coordinate of the sector ?

I have quickly mocked up the problem in the image above, please note it is B I am aiming to find.

Angle in rads = 0.262

Radius = 21

Arc length = 5.5

A = (0.5,21)

share|improve this question
    
You can use complex numbers to calculate the co-ordinates of the new points . Take the init point as $0.5+21i$ and multiply it with $e^{i\theta}$ where $\theta = $ the radians by which it is rotated –  trafalgar_law Mar 5 at 12:20
    
In contrast to your other question, this time you have too much information. The radis and angle tell you the arclength. –  bubba Mar 5 at 12:23

1 Answer 1

Same technique as in your other question here.

Let $A = (x,y)$ and let $B= (x_1, y_1)$. Then $$ x_1 = \; x\cos(0.262) + y\sin(0.262) \\ y_1 = -x\sin(0.262) + y\cos(0.262) \\ $$

This assumes the center is again at $(0,0)$.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.