Let Circle1 be a circumference, built using Circle with center point
Let Line1 be a line passing through the center A and a point B on the circumference, built using Line. This line intersects the circumference in a point C.
Build the perpendicular line to Line1, intersecting it in A and the circumference in N and O.
Build four segments, OC, CN, NB, BO, using Segment.
So, you obtain the desired square, infact, four equal chords correspond to the four equal angles centered in the origin, because they are rect.

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