A line which is divided into seven equal parts, shown by construction.
A line which is divided into equal parts, shown by construction and square.
Illustration of pentagon inscribed in circle. Or, circle circumscribed about pentagon. Construction…
An illustration of a zone of a sphere. A zone occurs when a sphere is cut by parallel planes that are…
An illustration of a zone of a sphere. A zone occurs when a sphere is cut by parallel planes that are…
An 8-inch sphere cut by parallel planes, one 2 inches from center and the other 6 inches from center.…
Lines drawn to horizontal to form triangle ratios (reference triangles, angles).
Lines drawn to horizontal to form triangle ratios (reference triangles, angles). Axes, quadrants, abscissa,…
A perpendicular line drawn from point P to straight line RS.
CD is the projection of AB upon OX. In each case AE=CD and AE=ABcos theta.
OP is a vector (directed quantity) showing the force by a weight acting on it at an angle of 20 degrees.
Illustration showing an angle of elevation from a horizontal line to a line of sight.
Illustration showing an angle of depression from a horizontal line to a line of sight.
Illustration showing an angle of 23 degrees 40 minutes making a triangle in a city block and marking…
Illustration showing a survey on the lake front in Chicago with distances and angle measures shown.
Spiral with lines AB and CD drawn on piece of paper shown flat.
Spiral with lines AB and CD drawn on piece of paper and rolled into a cylinder to form spiral running…
Coordinate axis with angle XOP equal to theta, Θ, and angle XOQ=180 - Θ. From any point in the terminal…
To illustrate the structure of nerve fibers. Labels: A, nerve fiber examined fresh; n, node. B, nerve…
Diagram of the outer surface of left cerebral hemisphere to illustrate the localization of functions.…
The right retina as it would be seen if the front part of the eyeball with the lens and vitreous humor…
Lines for the detection of astigmatism. "The refracting surfaces of the eye acting together are equivalent…
The larynx viewed from its pharyngeal opening. The back wall of the pharynx has been divided and its…
Surface of normal chest; outlines of cardiac dulness to the left of the sternum. The spaces enclosed…
The origins of the three glutaei upon the dorsum of the ilium (part of the hip bone). The gluteal lines…
An illustration showing when one straight line meets another straight line and makes the adjacent angles…
An illustration of two angles that are adjacent. They have the same vertex and a common side between…
An illustration showing a straight angle. When the sides of an angle extend in opposite directions,…
Vertical angles are when two angles have the same vertex, and the sides of the one are prolongations…
Illustration of two lines intersecting at a point. This can be used to show vertical angles.
Illustration of two straight lines drawn from a point in a perpendicular to a given line, cutting off…
Illustration showing only one perpendicular can be drawn to a given line from a given external point.
Illustration showing that the perpendicular is the shortest line that can be drawn to a straight line…
Illustration showing two lines CA and CB drawn from the point C to the extremities of the straight line…
Illustration showing two straight lines drawn from the same point in a perpendicular to a given line,…
Illustration showing two straight lines in the same plane perpendicular to the same straight line are…
Illustration showing if a straight line is perpendicular to one of two parallel lines, it is perpendicular…
Illustration showing that a transversal is a straight line that cuts two or more straight lines.
Illustration showing that if two parallel lines are cut by a transversal, then the alternate interior…
Illustration showing that when two straight lines in the same plane are cut by a transversal, if the…
Illustration showing that when two parallel lines are cut by a transversal, the exterior-interior angles…
Illustration showing that when two parallel lines are cut by a transversal, the two interior angles…
Illustration showing a triangle with an exterior segment drawn to show and exterior angle. This can…
Illustration of two parallel lines with equal segments between them. Two parallel lines are everywhere…
Illustration showing that when three or more parallel lines intercept equal parts on one transversal,…
Illustration of a triangle showing that when a line parallel to the base of a triangle bisects one side,…
Illustration of an axis of symmetry drawn with respect to a hexagon.
Illustration of an axis of symmetry drawn with respect to a hexagon.
Illustration of an axis of symmetry drawn with respect to a quadrilateral.
Illustration of a quadrilateral which has two adjacent sides equal and the other two sides equal. It…