Lines can be vertical, horizontal, diagonal or curved. Other shaped slits were used, including vertical and diagonal apertures. This means that is lower triangular with its eigenvalues on the diagonal. Screen sizes are measured in diagonal inches. Twill is a type of textile weave with a pattern of diagonal parallel ribs. The second square is constructed by flipping the first square along the main diagonal. The entries of a symmetric matrix are symmetric with respect to the main diagonal. The primary square is constructed by flipping the root square about the main diagonal. The eigenvalues of a diagonal matrix are the diagonal elements themselves. The planking is edge nailed on a diagonal. It is the length of the space diagonal of a unit cube. The adjugate of a diagonal matrix is again diagonal. Note there is a trivial symmetry across the diagonal since . Sometimes the figure is standing on a globe inscribed with a diagonal cross. The eigenvalues are still on the main diagonal.