Use the tools in the applet to construct a square with AB as one of its sides.[br][br]Explore. Try to do this on your own.[br]If you need more help, there are detailed instructions and a video at the bottom.

You start with segment AB.[br]Use the LINE tool to make this line AB.[br][br]Use the compass tool to make a circle from A to B (Center is at A).[br]Mark the other intersection as point C. [br]Segments AB and AC are congruent because both are radii of circle A.[br][br]Construct two more circles. One is from C to B. The other is from B to C.[br]Mark the points where these two circles intersect as D (on top) and E (on bottom).[br]DE is the perpendicular bisector of segment BC. They intersect at right angles.[br]This is important, because this will make part of our square.[br][br]Mark the intersection of circle A and segment DA. Call it F. AF and AB are two sides of the square.[br][br]Finally, make two more circles and their intersection: from D to A and from B to A. Call the intersection G.[br][br]You should have ABGF is a square. [br]Use the POLYGON tool to make it a square.[br][br]Do the DRAG TEST to verify it is a square.