"Draw lines parallel to AB and CD at distant R from them. The intersection of these lines will be center of the required arc." —French, 1911

Draw Arc of Given radius R Tangent to Two Given Lines

"Draw lines parallel to AB and CD at distant R from them. The intersection of these lines will be center…

Illustration used to show how to "find an arc of a circle having a known radius, which shall be equal in length to a given straight line."

Construction Of Arc

Illustration used to show how to "find an arc of a circle having a known radius, which shall be equal…

Bones of the arm and hand. Labels: a, large end of ulna; b, radius; c, small end of the ulna; d, carpal bones; e, metacarpal bones; f, first row of the bones of the fingers.

Bones of the Arm and Hand

Bones of the arm and hand. Labels: a, large end of ulna; b, radius; c, small end of the ulna; d, carpal…

The skeleton of the arm and leg. Labels: H, the humerus; Cd, its articular head which fits into the glenoid fossa of the scapula; U, the ulna; R, the radius; O, the olecranon; Fe, the femur; P, the patella; Fi, the fibula; T, the tibia.

Arm and Leg Skeleton

The skeleton of the arm and leg. Labels: H, the humerus; Cd, its articular head which fits into the…

"The bones of the arm. a, humerus; b, ulna; c, radius; d, the carpus; e, the fifth metacarpal; f, the three phalanges of the fifth digit (little finger)." —Martin, 1917

Arm Bones

"The bones of the arm. a, humerus; b, ulna; c, radius; d, the carpus; e, the fifth metacarpal; f, the…

Bones of the arm. Labels: A, arm in supination; B, arm in pronation. H, humerus; R, radius; U, ulna.

Bones of the Arm

Bones of the arm. Labels: A, arm in supination; B, arm in pronation. H, humerus; R, radius; U, ulna.

Transverse section through the middle of the right forearm, in the position of semipronation.

Transverse Section Through Arm

Transverse section through the middle of the right forearm, in the position of semipronation.

"A current is caused to pass from the mercury through C along the radius of the disc A through the field of magnetic force due to the horse-shoe magnet NO. The result is that the wheel rotates in the direction indicated by the arrow." — Encyclopedia Britannica, 1893

Barlow Apparatus

"A current is caused to pass from the mercury through C along the radius of the disc A through the field…

Biceps muscle attached to the radius.

Biceps Muscle and Radius

Biceps muscle attached to the radius.

An illustration of a vertical cross section of the spherical zones of a casting with a diameter of 16 inches.

Vertical Cross Section of Spherical Zones of a Casting

An illustration of a vertical cross section of the spherical zones of a casting with a diameter of 16…

An illustration showing how to construct a center and radius of a circle that will tangent the three sides of a triangle. "Bisect two of the angles in the triangle, and the crossing C is the center of the required circle."

Construction Of The Center And Radius Of A Circle Tangent To Triangle Sides

An illustration showing how to construct a center and radius of a circle that will tangent the three…

A circle with labels for radius, diameter, and circumference. The visual will help to remember what each term means.

Circle Parts

A circle with labels for radius, diameter, and circumference. The visual will help to remember what…

Illustration used to show that "A tangent to a circle is perpendicular to the radius drawn to the point of tangency."

Tangent to Perpendicular Radius Circle Theorem

Illustration used to show that "A tangent to a circle is perpendicular to the radius drawn to the point…

Equal circles inside and tangent to the outside circle, also tangent to each other

Circle to Circle Tangents

Equal circles inside and tangent to the outside circle, also tangent to each other

Illustration of circle with 10 inch diameter and square.

Circle With 10 inch Diameter and Steel Square

Illustration of circle with 10 inch diameter and square.

Circle with 36 degree angles marked. This diagram can be used with the following trig problem: Locate the centers of the holes B and C by finding the distance each is to the right and above the center O. The radius of the circle is 1.5 inches. Compute correct to three decimal places.

Circle With 36 degree Angles and Radius 1.5 in.

Circle with 36 degree angles marked. This diagram can be used with the following trig problem: Locate…

Illustration of circle with 6 inch diameter.

Circle With 6 inch Diameter

Illustration of circle with 6 inch diameter.

Illustration of circle with 8 inch diameter.

Circle With 8 inch Diameter

Illustration of circle with 8 inch diameter.

An illustration used to show how the area of a circle is calculated. Area is equal to the product of pi and the radius squared.

Area Of A Circle

An illustration used to show how the area of a circle is calculated. Area is equal to the product of…

Circle modeling the earth. O is the center of the earth, r the radius of the earth, and h the height of the point P above the surface; it is required to find the distance from the point P to the horizon at A.

Circle With Center o and Radius r with point P

Circle modeling the earth. O is the center of the earth, r the radius of the earth, and h the height…

Circle with chord AB=2 ft. and radius OA = 3 ft.. Triangle AOC is a right triangle. Angle AOC=half angle AOB, and the central angle AOB has the same measure as the arc AnB.

Circle With a Chord of 2 ft. and a Radius of 3 ft.

Circle with chord AB=2 ft. and radius OA = 3 ft.. Triangle AOC is a right triangle. Angle AOC=half angle…

Illustration of a circle with diameter AB. Radii are RO, SO, AO, and BO. ED is a chord.

Chords, Diameters, and Radii of a Circle

Illustration of a circle with diameter AB. Radii are RO, SO, AO, and BO. ED is a chord.

Illustration of a circle with diameter BC, chord DF, secant MN, and tangent HK.

Chords, Secants, Diameters, and Tangents of a Circle

Illustration of a circle with diameter BC, chord DF, secant MN, and tangent HK.

Illustration showing a circle with a diameter, radius, and segment drawn.

Circle With Diameter, Radius, Segment

Illustration showing a circle with a diameter, radius, and segment drawn.

Illustration showing a circle with a diameter, radius, lines, triangle, and segment drawn.

Circle With Diameter, Radius, Segment, Line

Illustration showing a circle with a diameter, radius, lines, triangle, and segment drawn.

Circle with diameter, radius, arc, chord, and arc.

Circle With Parts

Circle with diameter, radius, arc, chord, and arc.

Illustration of circle with arc, chord, diameter  and radius.

Parts of Circle

Illustration of circle with arc, chord, diameter and radius.

An illustration showing a quadrilateral inscribed in a circle that is tangent to a line.

Quadrilateral Inscribed In A Circle

An illustration showing a quadrilateral inscribed in a circle that is tangent to a line.

Illustration of circle with radius of 4000, and triangle with 45 degree angle enclosed.

Circles With Radius 4000 and Enclosed Triangle

Illustration of circle with radius of 4000, and triangle with 45 degree angle enclosed.

Illustration of a circle with the radius OA drawn and labeled.

Radius of Circle

Illustration of a circle with the radius OA drawn and labeled.

Illustration of a circle with radius QR.

Radius of a Circle

Illustration of a circle with radius QR.

An illustration showing a circle with radius r, diameter d, and chord c.

Radius, Diameter, and Chord In A Circle

An illustration showing a circle with radius r, diameter d, and chord c.

Illustration of circle with diameter and segment used to find area.

Circle With Diameter and Segment labeled

Illustration of circle with diameter and segment used to find area.

An illustration showing a triangle with sides b, c, and d inscribed in a circle with radius r.

Triangle Inscribed In A Circle

An illustration showing a triangle with sides b, c, and d inscribed in a circle with radius r.

An illustration showing a triangle with angles A, C, and D inscribed in a circle which is tangent to a line.

Triangle Inscribed In A Circle

An illustration showing a triangle with angles A, C, and D inscribed in a circle which is tangent to…

Illustration showing a circle with an inscribed triangle and radii.

Circle With Inscribed Triangle and Radii

Illustration showing a circle with an inscribed triangle and radii.

Illustration showing a circle with various chords drawn.

Circle With Various Chords

Illustration showing a circle with various chords drawn.

Illustration showing a circle with various chords drawn.

Circle With Various Chords

Illustration showing a circle with various chords drawn.

Illustration showing a circle with various chords and tangents drawn.

Circle With Various Chords And Tangents

Illustration showing a circle with various chords and tangents drawn.

Illustration showing a circle with various chords and tangents drawn.

Circle With Various Chords And Tangents

Illustration showing a circle with various chords and tangents drawn.

Illustration of three circles enclosed in an equilateral triangle.

Circles Enclosed in Equilateral Triangle

Illustration of three circles enclosed in an equilateral triangle.

Illustrations of 2 equal circles with radii drawn.

Equal Circles With Radii

Illustrations of 2 equal circles with radii drawn.

Illustrations of 2 equal circles with radii drawn.

Equal Circles With Radii and Chords

Illustrations of 2 equal circles with radii drawn.

Illustration of large circle and square with 4 smaller circles inside.

Circles Inside of a Square

Illustration of large circle and square with 4 smaller circles inside.

Intersecting circles with chords and radii.

Intersecting Circles

Intersecting circles with chords and radii.

Illustration of box filled with pipes.

Circular Pipes in Box

Illustration of box filled with pipes.

Illustration of of construction of a radius when given only a part of the circumference.

Construction of Radius When Given Only a Part of the Circumference

Illustration of of construction of a radius when given only a part of the circumference.

Illustration of of construction of a radius when given only a part of the circumference.

Construction of Radius When Given Only a Part of the Circumference

Illustration of of construction of a radius when given only a part of the circumference.

Illustration of blueprint used by highway engineers to widen the pavement on the inside of the curve of a road.

Curve in Pavement of Road

Illustration of blueprint used by highway engineers to widen the pavement on the inside of the curve…

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius of curvature of the inner face of an annular lens. The outer face is the same as that of an ordinary annular lens, which the other face, though straight in the vertical, is ground to the required curve in the horizontal plane. The rays f'fc falling upon the lens x converge to the vertical focal plane ff and afterwards diverge through the smaller horizontal angle x'f'x', and so for any other case." —The Encyclopedia Britannica, 1910

Differential Lens

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the…

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius of curvature of the inner face of an annular lens. The outer face is the same as that of an ordinary annular lens, which the other face, though straight in the vertical, is ground to the required curve in the horizontal plane. The rays f'fc falling upon the lens x converge to the vertical focal plane ff and afterwards diverge through the smaller horizontal angle x'f'x', and so for any other case." —The Encyclopedia Britannica, 1910

Differential Lens

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the…

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the radius of curvature of the inner face of an annular lens. The outer face is the same as that of an ordinary annular lens, which the other face, though straight in the vertical, is ground to the required curve in the horizontal plane. The rays f'fc falling upon the lens x converge to the vertical focal plane ff and afterwards diverge through the smaller horizontal angle x'f'x', and so for any other case." —The Encyclopedia Britannica, 1910

Differential Lens

"Differential Lens.—Horizontal divergence may be obtained to any required amount by varying the…

Right elbow joint, cut through at right angles to the axis of trochlea humeri, from the ulnar side.

Elbow Joint

Right elbow joint, cut through at right angles to the axis of trochlea humeri, from the ulnar side.

A view from behind of a frontal section through the right elbow joint.

Frontal Section Through Elbow Joint

A view from behind of a frontal section through the right elbow joint.

Left elbow joint, showing posterior and external ligaments.

Elbow Showing External Ligaments

Left elbow joint, showing posterior and external ligaments.

Left elbow joint, showing anterior and internal ligaments.

Elbow Showing Internal Ligaments

Left elbow joint, showing anterior and internal ligaments.

Frontal section of the elbow, viewed from in front.

Frontal Section Through the Elbow

Frontal section of the elbow, viewed from in front.

Sagittal section of the right elbow, with the arm in pronation.

Sagittal Section of the Elbow

Sagittal section of the right elbow, with the arm in pronation.

"Right fore foot of Indian Elephant. U, ulna; R, radius; c, cunelform; l, lunar; sc, scaphold; u, unciform; m, magnum; td, trapezoid; tm, trapezium; I to V, first to fifth digit." —The Encyclopedia Britannica, 1903

Elephant Foot

"Right fore foot of Indian Elephant. U, ulna; R, radius; c, cunelform; l, lunar; sc, scaphold; u, unciform;…

Illustration of half of an ellipse. "The ordinates of two corresponding points in an ellipse and its auxiliary circle are in the ratio b:a."

Corresponding Points in an Ellipse and Circle

Illustration of half of an ellipse. "The ordinates of two corresponding points in an ellipse and its…