Lines drawn to horizontal to form triangle ratios (reference triangles, angles). Axes, quadrants, abscissa,…

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

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…

Illustration of a man using a cross-staff, a navigation tool used largely at sea. It was originally…

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

"The radiation of light, or the intensity of light is inversely proportional to the square of the distance…

"Another illustration of how luminous density varies inversely as the square of the distance." —Croft…

"A card placed at point A receives normal light. At point B the card receives four times as much light,…

"Let a be the distance at which an object can be see distinctly, and b, the distance at which the same…

"Relative distance of the Planets. Having now given a short account of each planet composing the solar…

Roof with a slope of 30 degrees. Angle theta is the inclination to the horizontal of the line AB, drawn…

An illustration of a square and triangles within the square. This is an example of a problem that can…

Two set squares, whose sides are 3,4, and 5 in., are placed so that their 4-in. sides and right angles…

Illustration of oblique triangle used to find distance across a river.

Illustration of oblique triangle used to find distance across a river.

Illustration of oblique triangle used to find distance across a lake.

Inclined plane forming right triangle showing the velocity of a body sliding a distance,s, down a smooth…

Illustration of similar triangles used to find distance across a lake.

Illustration of similar triangles used to find distance across a stream

"The wedge is a movable inclined plane, and is used for moving a great weight a short distance. A common…