# Draw an Arc - Given an angle and one segment

Is given an angle £ and an segment AB. Haw can I draw an arc from A to B such the central angle corresponding to it to be £ ?

If you find any point $$C$$ such that $$\angle ACB = £/2$$, then the $$AB$$ arc of the circumcircle of $$\triangle ABC$$ will work.
You can do this by finding any two angles that add to $$180^\circ - £/2$$, and drawing one of them at $$A$$ and the other one at $$B$$, both with $$AB$$ as one of the angle legs, and let $$C$$ be where the two new angle legs intersect.