Edges of plywood straight and square inspection and Test
1.Diagonal measures 5′ at the 3′ mark of a 4′ wide sheet of plywood, then the corner is square. Just remember: Not all plywood is exactly 4′ wide.This is based on the right-angled principle.
The sum of squares of two right-angled sides equals the square of the oblique side.
2.A string or a chalkline makes a ready reference for checking the straightness of a sheet of plywood.
3.Measure whether the diagonals are the same, and if they are the same, they are right-angled. If not, it’s not a right angle.