1) Use the Line tool[icon]/images/ggb/toolbar/mode_join.png[/icon] to create a line between the center of the circle and the point on the circle. This could be ANY point on the circle. Using the given point will match your square up with the red square shown.[br]2) Use the Intersect tool[icon]/images/ggb/toolbar/mode_intersect.png[/icon] to mark the point where that line and the circle intersect.[br]3) Create a line perpendicular to the line from step 1 that goes through the center of the circle.[br]4) Use the Intersect tool[icon]/images/ggb/toolbar/mode_intersect.png[/icon] to mark the points where this line intersects the circle.[br]5) Use the Polygon tool[icon]/images/ggb/toolbar/mode_polygon.png[/icon] to create your square from the four points on the circle.[br]6) Use the Angle Measure tool[icon]/images/ggb/toolbar/mode_angle.png[/icon] and the Distance tool[icon]/images/ggb/toolbar/mode_distance.png[/icon] to verify that the result is a square.