11. As shown to the left, in the conrotatory transition state there is a ? mirror plane of symmetry . 12. The energy of sunlight which enters the mirror parallel to its plane of symmetry is focused along the solar cookers. 13. The ibex was paraxonic, with the plane of symmetry of each foot passing between the third and fourth digits. 14. Its blades feature a symmetrical airfoil with its plane of symmetry in the plane of rotation and perpendicular to the air stream. 15. There are two main categories of spinnakers, symmetric and asymmetric depending on whether a plane of symmetry exists for that particular sail. 16. An inverted mark along the horizontal or sagittal plane of symmetry indicates a socially inferior rank to that indicated by the primary mark. 17. This transverse plane has infinite planes of symmetry and thus, within this plane, the material properties are the same in all directions. 18. The hexagonal bipyramid has a plane of symmetry ( which is rhombic and lie at 30?angles to each other, perpendicular to the horizontal plane. 19. The meso compound is bisected by an internal plane of symmetry that is not present for the non-meso isomers ( indicated by an X ). 20. You can get an achiral object from the combination of chiral sub-parts, if you attach the two mirror images across the plane of symmetry .