Bone points and bone needles. Crafted during the Reindeer age.

Illustration used to construct a circle when given three points.

Illustration of a circle which illustrates that the tangents to a circle drawn from an external point…

Illustration to let fall a perpendicular upon a given line from a given external point.

Illustration of the construction of a perpendicular to a line when given a point O on the straight line.

Illustration of the construction of a perpendicular to a line when given a point B on the straight line.

"CELESTIAL CROWN. Distinguished from any other crown by the stars on the points or rays that proceed…

Illustration showing that the perpendicular is the shortest line that can be drawn to a straight line…

Illustration showing two straight lines drawn from the same point in a perpendicular to a given line,…

Illustration showing only one perpendicular can be drawn to a given line from a given external point.

Illustration that shows if two parallel lines are cut by three or more transversals that pass through…

Illustration that shows if two parallel lines are cut by three or more transversals that pass through…

Illustration to show the perpendiculars dropped from any point in the equilateral triangle to the three…