@Article{CMR-27-378, author = {Chen , ZhizhiLin , Wei and Luo , Lü-Lin}, title = {Projections, Birkhoff Orthogonality and Angles in Normed Spaces}, journal = {Communications in Mathematical Research }, year = {2021}, volume = {27}, number = {4}, pages = {378--384}, abstract = {
Let $X$ be a Minkowski plane, i.e., a real two dimensional normed linear space. We use projections to give a definition of the angle $A_q(x, y)$ between two vectors $x$ and $y$ in $X$, such that $x$ is Birkhoff orthogonal to $y$ if and only if $A_q(x, y) = \frac{π}{2}$. Some other properties of this angle are also discussed.
}, issn = {2707-8523}, doi = {https://doi.org/}, url = {http://global-sci.org/intro/article_detail/cmr/19081.html} }