1. Use a straightedge to draw line m and label a point on the line as point F
2. Construct a line perpendicular to line m through point F. Label a point on this line as point G.
3. With the compass open to the desired side length of the square, place the compass point on point F and draw an arc on line m and an arc on FG←→ . Label the points of intersection as points H and K.
4. Without changing the compass width, place the compass point on point H and draw an arc in the interior of ∠HFK.
5. Keeping the same compass width, place the compass on point K and draw an arc in the interior of ∠HFK to intersect the previously drawn arc. Label the point of intersection as point J.
6. Use the straightedge to draw JH¯¯¯¯¯ and JK¯¯¯¯¯.