Construct a square ABCD whose AC-AB=3cm

mark A

construct AB
Mark circle of radius AB+3, center A
construct perpendicular at B
where the circle intersects the perpendicular is C.
now construct AD and CD

You must carry the A to the B and subtract 21 from 😞

To construct a square ABCD with AC - AB = 3cm, you will need to follow these steps:

1. Start by drawing a line segment AB of any length. Let's say AB is 1cm.

2. From point B, draw a line segment BC perpendicular to AB. The length of BC would also be 1cm to maintain the initial square shape.

3. Draw a line segment CD parallel to AB, with a length of 4cm (AB + AC = 1cm + 3cm = 4cm).

4. From point C, draw a line segment DA perpendicular to AB, with a length of 4cm (the same length as CD).

5. Connect point A with D to complete the square ABCD.

6. Measure the diagonals AC and AB using a ruler. Verify that the difference between AC and AB is indeed 3cm.

It's important to note that there can be multiple solutions for a square with AC - AB = 3cm, as long as the lengths of the sides and diagonals satisfy this condition.