We survey elementary results in Minkowski spaces (i.e. finite dimensional
Banach spaces) that deserve to be collected together, and give simple proofs
for some of them. We place special emphasis on planar results. Many of these
results have often been rediscovered as lemmas to other results. In Part I we
cover the following topics: The triangle inequality and consequences such as
the monotonicity lemma, geometric characterizations of strict convexity,
normality (Birkhoff orthogonality), conjugate diameters and Radon curves,
equilateral triangles and the affine regular hexagon construction, equilateral
sets, circles: intersection, circumscribed, characterizations, circumference
and area, inscribed equilateral polygons.