How to Find Square Layout Lines
By: Joe Truini
If laying out square lines is part of your next home improvement project, here’s a great way to do it using the Pythagorean theorem (A² + B² = C²) to form a right angle triangle with 3′ and 4′ sides and a diagonal of 5′:
- Establish a 4′ line parallel to a wall.
- Measure out 3′ from one end of the 4′ line roughly perpendicular to it.
- Hold a tape measure on the other end of the 4′ line.
- Measure 5′ so it forms a triangle with the end of the 3′ line.
- Adjust the angle of the 3′ line until the tape measure aligns with it.