"Break lathes can take in work of considerable length as well as of large diameter,—the treble-geared…

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

Illustration of a circle with an inscribed angle that can be used to prove that "An inscribed angle…

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

Illustration of circle with 10 inch diameter and square.

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

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.

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

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

"If from any point on the circumference of a circle, a perpendicular be let fall upon a given diameter,…

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

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

Illustration of a regular hexagon inscribed in a circle. This can also be described as a circle circumscribed…

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

Illustration of a square, with diagonals drawn, circumscribed about a circle. This can also be described…

Illustration of a square, with 1 diagonals drawn, circumscribed about a circle. This can also be described…

Illustration of a square circumscribed about a circle. This can also be described as a circle inscribed…

Illustration of a square inscribed in a circle. This can also be described as a circle circumscribed…

Illustration of a square, with diagonals drawn, inscribed in a circle. This can also be described as…

Illustration showing a circle with various chords and tangents drawn.

Illustration showing a circle with various chords and tangents drawn.

Illustration of three circles enclosed in an equilateral triangle.

"The Earth, whose diameter is 7,912 miles, is represented by the globe, or sphere. The straight line…

Illustration showing that if one diameter is conjugate to a second, the second is conjugate to the first.

"Epicycloidal wheel, a wheel or ring fixed to a framework, toothed on its inner side, and having in…

Three suspended concentric circles free to move independently of each other at right angles.

Any two conjugate diameters of an hyperbola are harmonic conjugates with regard to the asymptotes.

"The principle of increased velocity as bodies descend from a height, is curiously illustrated by pouring…

The magic circle of circles, first developed by Benjamin Franklin, consists of eight annular rings and…

Illustration of a circle with center O and diameters AB and CD perpendicular to each other.

An illustration of a ring (circle within circle), with diameters of 3a-7 and 6a+9. Illustration could…

Illustration of ring (small circle in larger concentric circle) with piece cut out.

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

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.

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 cut into polygons as bases with their vertices at the center of sphere.

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

An illustration of a sphere showing diameter, arcs, and circles. A sphere is a solid bounded by a curved…

An illustration of a sphere showing diameter, arcs, and circles. A sphere is a solid bounded by a curved…