Illustration of ring (small circle in larger concentric circle) sprung into place.

Ring Sprung Into Place

Illustration of ring (small circle in larger concentric circle) sprung into place.

This illustrates how to determine the force required to turn a connecting rod of a steam engine.

Connecting Rod of a Steam Engine

This illustrates how to determine the force required to turn a connecting rod of a steam engine.

A secant is "a line which cuts a figure in any way. Specifically, in trigonometry, a line from the center of a circle through one extremity of an arc (whose secant it is said to be) to the tangent from the other extremity of the same arc; or the ratio of this line to the radius; the reciprocal of the cosine. The ratio of AB to AD is the secant of the angle A; and AB is the secant of the arc CD." —Whitney, 1889

Circle with Secant

A secant is "a line which cuts a figure in any way. Specifically, in trigonometry, a line from the center…

"In geometry: (a) A plane figure inclosed between the arc of a circle, ellipse, or other central curve and two radii to its extremities from the center. Thus, in the figure, CDB is a sector of a circle." -Whitney, 1911

Sector

"In geometry: (a) A plane figure inclosed between the arc of a circle, ellipse, or other central curve…

An illustration showing a circle sector with radius r, center/central angle v, and length of circle arc b.

Circle Sector

An illustration showing a circle sector with radius r, center/central angle v, and length of circle…

An illustration showing a circle sector with center/central angle v and polygon angle w.

Circle Sector

An illustration showing a circle sector with center/central angle v and polygon angle w.

An illustration showing a circle sector with height of segment h and radius r.

Circle Sector

An illustration showing a circle sector with height of segment h and radius r.

Illustration of a semicircle.

Semicircle

Illustration of a semicircle.

Illustration of a semicircle with chords and radii.

Semicircle With Chords and Radii

Illustration of a semicircle with chords and radii.

An 8-inch sphere cut by parallel planes, one 2 inches from center and the other 6 inches from center. This illustration can be used to find the area of the zone and the volume of the segments.

Sphere With 8-inch Diameter Cut by Planes

An 8-inch sphere cut by parallel planes, one 2 inches from center and the other 6 inches from center.…

An illustration of a sphere inside of a cylinder with radius/diameter labeled. Illustration for showing how volume is found.

Sphere Inside of Cylinder.

An illustration of a sphere inside of a cylinder with radius/diameter labeled. Illustration for showing…

Illustration of a sphere with a tangent plane. "A plane perpendicular to a radius at its extremity is tangent to the sphere."

Sphere With Tangent Plane

Illustration of a sphere with a tangent plane. "A plane perpendicular to a radius at its extremity is…

Illustration of a sphere with a tangent plane. "A plane perpendicular to a radius at its extremity is tangent to the sphere."

Sphere With Tangent Plane

Illustration of a sphere with a tangent plane. "A plane perpendicular to a radius at its extremity is…

An illustration of a sphere showing a radius of 1 foot. Illustration could be used for calculating volume.

Sphere With a Radius of 1 foot

An illustration of a sphere showing a radius of 1 foot. Illustration could be used for calculating volume.

An illustration of a zone of a sphere. A zone occurs when a sphere is cut by parallel planes that are equal distances apart. This illustration is the segment of one base.

Zones or Segments of Spheres

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 equal distances apart. This illustration is the segment of two bases.

Zones or Segments of Spheres

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 flanged spherical segment with a diameter of 10 inches. Illustration could be used to find the area.

Flanged Spherical Segment

An illustration of a flanged spherical segment with a diameter of 10 inches. Illustration could be used…

An illustration showing how to construct a square circumscribed about a circle. "Draw the diameters AB and CD at right angles to one another; with the radius of the circle, and A, B, C, and D as centers, draw the four dotted half circles which cross one another in the corners of the square, and thus complete the problem."

Construction Of A Square Circumscribed About A Circle

An illustration showing how to construct a square circumscribed about a circle. "Draw the diameters…

An illustration showing how to construct a square inscribed in a circle. "Draw the diameter AB, and through the center erect the perpendicular CD, and complete the square as shown in the illustration."

Construction Of A Square Inscribed In A Circle

An illustration showing how to construct a square inscribed in a circle. "Draw the diameter AB, and…

Illustration of radius drawn to point of contact of a tangent.

Point of Tangency

Illustration of radius drawn to point of contact of a tangent.

An illustration showing how to construct a tangent to 2 given circles of different diameters. "Join the centers C and c of the given circles, and extend the line to D; draw the radii AC and ac parallel with one another. Join Aa, and extend the line to D. On CD as a diameter, draw the half circle CeD; on cD as a diameter, draw the half circle cfD; then the crossings e and f are the tangenting points of the circles."

Construction Of Tangent To 2 Circles

An illustration showing how to construct a tangent to 2 given circles of different diameters. "Join…

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

Circle Inscribed In A Triangle

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

An illustration showing a circle with sectors D and E inscribed in a triangle with angles, A, B, and C.

Circle Inscribed In A Triangle

An illustration showing a circle with sectors D and E inscribed in a triangle with angles, A, B, and…

Anterior view of the ulna (bone of the arm) of the left side. Labels: 1, olecranon process; 2, greater sigmoid cavity; 5, external surface; 6, ridge for interosseous ligament; 7, small head for the radius; 8, carpal surface.

Ulna

Anterior view of the ulna (bone of the arm) of the left side. Labels: 1, olecranon process; 2, greater…

"The <em>ulna</em>, or elbow bone, is the larger of these two bones. It is joined to the humerus by a hinge joint at the elbow. It is on the same side as the little finger. The <em>radius</em>, queerly named because it is supposed to resemble one of the spokes of a wheel, is the long, slightly curved, outer bone fo the forearm. It is on the same side as the thumb. Its upper end is fastened both to the ulna and the humerus." — Blaisedell, 1904

Ulna and Radius

"The ulna, or elbow bone, is the larger of these two bones. It is joined to the humerus by…

The Ulna and Radius. Labels: 1, radius; 2, ulna; o, olecranon process, on the anterior surface of which are seen the large (gs) and the small (ls) cavities for the reception of the lower end of the humerus and of the head of the radius, respectively; h, head of radius.

The Human Ulna and Radius

The Ulna and Radius. Labels: 1, radius; 2, ulna; o, olecranon process, on the anterior surface of which…

Fracture of upper third of ulna, with dislocation of radius forward.

Fractured Ulna with Dislocation of Radius

Fracture of upper third of ulna, with dislocation of radius forward.

A wheel is a circular device that is capable of rotating on its axis, facilitating movement and transportation.

Side View of a Vehicle Wheel

A wheel is a circular device that is capable of rotating on its axis, facilitating movement and transportation.

"Ideal fore limb. H., Humerus; R., radius; U., ulna; r'., radiale; u'., ulnare; i., intermedium; c., centrale; 1-5, carpalia bearing the corresponding digits with metacarpals (mc.) and phalanges (ph)." -Thomson, 1916

Vertebrate Fore Limb

"Ideal fore limb. H., Humerus; R., radius; U., ulna; r'., radiale; u'., ulnare; i., intermedium; c.,…

"Skeleton of Egyptian Vulture. (Neophron percnopterus), to show bones of bird. a, post-orbital process; b, lower jaw; c, cervical vertebra; co, coracoid bone; d, humerus; e, radius; f, ulna; g, metacarpus; h, second phalanx of chief digit of wing; h, phalanges of lower digit; h'', first phalanx of chief digit; i, clavicle; k, sternum; l, pelvis; m, coccyx; n, femur; o, tibia; p, tarso-metatarsus; q, phalanges of foot." &mdash; Winston's Encyclopedia, 1919

Vulture Skeleton

"Skeleton of Egyptian Vulture. (Neophron percnopterus), to show bones of bird. a, post-orbital process;…

Ligaments on anterior aspect of radio carpal, carpal, and carpo metacarpal joints.

Ligaments of the Wrist

Ligaments on anterior aspect of radio carpal, carpal, and carpo metacarpal joints.

Transverse section through the wrist, showing the annular ligaments and the canals for the passage of the tendons.

Transverse Section Through the Wrist

Transverse section through the wrist, showing the annular ligaments and the canals for the passage of…