Angles in baseball can be categorized as right (exactly 90 degrees), obtuse (greater than 90 degrees), or acute (less than 90 degrees). Opposite rays share a common endpoint and are collinear, while a bisector splits an angle into two equal halves. A linear pair are adjacent angles whose non-common sides are opposite rays and measure 180 degrees. Vertical angles formed by intersecting lines are congruent, complementary angles sum to 90 degrees, and supplementary angles sum to 180 degrees.