Hyperbolic geometry goes against common sense about what straight and parallel lines are. This can be confusing, but to understand it you have to ignore this confusion. It is possible to draw one and only one straight line from any point to any point. From each end of a finite straight line it is possible to produce it continuously in a straight line by an amount greater than any assigned length. It is possible to describe one and only one circle with any centre and radius.
All right angles are equal to one another.
To help explain this. Definitions Hyperbolic geometry uses terms, which may be unfamiliar, so here are their definitions. A Saccheri quadrilateral has a pair of equal opposite sides, which have one of the other sides as a common perpendicular. This common perpendicular is called the base, the side opposite is the summit, and the angles adjacent to the summit are the summit angles. The asymptotic parallels through a point to a straight line make equal, acute angles with the perpendicular from the point to the straight line.