Inscribe an equilateral triangle inside a triangle

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Given a triangle ΔABC, how to draw all possible inscribed equilateral triangles with given side whose vertices lie on different sides of ΔABC? enter image description here

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Take a point $P$ on a side of $ABC$ and rotate $ABC$ around $P$ by $60^\circ$ clockwise/counterclockwise. The intersections between the sides of the rotated triangle and the original triangle provide two points $Q,R$ such that $PQR$ is equilateral. In follows that there are infinite equilateral triangles inscribed in a given triangle. On the other hand, if the sides length is fixed, there are at most two solutions. I am going to provide a proof almost-without words:

enter image description here

The red locus is convex (since it is the arc of an ellipse centered at the upper vertex), hence it cannot meet the horizontal side at more than two points.