 Reference Angles/Triangles Formed by Angles in Quadrants With Labels

Lines drawn to horizontal to form triangle ratios (reference triangles, angles). Axes, quadrants, abscissa,… 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… 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 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… Curve in Pavement of Road

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

To determine the distance between two points A, B given by their projections. Military Distance Measurement

An illustration of military personnel measuring distance. Light Intensity

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

"Another illustration of how luminous density varies inversely as the square of the distance." —Croft… Light Intensity at Different Distances

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

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

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

Illustration modeling the path of a projectile. Roof With 30 degree Inclination for Trigonometry Triangle Problems

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

These are skew bevel wheels, made of a hyperboloid of revolution around an axis. Square

An illustration of a square and triangles within the square. This is an example of a problem that can… Two Squares With Sides of Lengths 3,4,5 Placed at Right Angles to Each Other

Two set squares, whose sides are 3,4, and 5 in., are placed so that their 4-in. sides and right angles… Oblique Triangle for Distance Across a River

Illustration of oblique triangle used to find distance across a river. Oblique Triangle for Distance Across a River

Illustration of oblique triangle used to find distance across a river. Oblique Triangle for Distance Across Lake

Illustration of oblique triangle used to find distance across a lake. Inclined Plane Forming Right Triangle

Inclined plane forming right triangle showing the velocity of a body sliding a distance,s, down a smooth… Similar Triangles for Distance Across Lake

Illustration of similar triangles used to find distance across a lake. Similar Triangles for Distance Across Stream

Illustration of similar triangles used to find distance across a stream Wedge

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