 ### Equal Dihedral Angles

Illustration of 3 equal dihedral angles. "Two dihedral angles have the same ratio as their plane angles." ### Bag with Ten Marbles

Bag with four white, four striped, and two black marbles used for a probability activity. ### Bag with Ten Marbles

Bag with four white, three black, and three striped marbles used for a probability activity. ### Bag with Ten Marbles

Bag with four striped, three black, and three white marbles used for a probability activity. ### Bag with Ten Marbles

Bag with four black, four white, and two striped marbles used for a probability activity. ### Bag with Ten Marbles

Bag with four black, three white, and three striped marbles used for a probability activity. ### Bag with Ten Marbles

Bag with four black, four striped, and two white marbles used for a probability activity. ### Circle and Triangle

Circle with triangle to show how to divide a line in extreme and mean ratio. ### Unit Circle

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane. The… ### Unit Circle Labeled At Quadrantal Angles

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled At Special Angles

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled At Special Angles

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled In 30° Increments With Values

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled In 45 ° Increments

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled In 45° Increments With Values

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled In 45° Increments With Values

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled With Quadrantal Angles And Values

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane. All… ### Unit Circle Labeled With Quadrantal Angles And Values

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled With Quadrantal Angles And Values

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled With Quadrantal Values

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane. At each… ### Unit Circle Labeled With Quadrantal Values

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled With Special Angles And Values

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled With Special Angles And Values

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Labeled With Special Angles And Values

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane with… ### Unit Circle Marked At Special Angles

Illustration of a unit circle (circle with a radius of 1) superimposed on the coordinate plane. All… ### Equal Circles With Intercepted Arcs

Illustration of equal circles to show that two central angles have the same ratio as their intercepted… ### 2 Similar Right Circular Cones

Illustration of 2 right circular cones that are similar. ### 2 Similar Cylinders

Illustration of 2 similar cylinders. The height and diameter of the smaller cylinder is half that of… ### 2 Soup Can Cylinders

Illustration of 2 soup cans that are similar cylinders. The diameter and height of the smaller can is… ### 3 Similar Cylinders

Illustration of 3 similar cylinders. The height and diameter in each successively smaller cylinder is… ### 3 Similar Cylinders

Illustration of 3 similar cylinders. The height and diameter in each successively smaller cylinder is… ### Corresponding Points in an Ellipse and Circle

Illustration of half of an ellipse. "The ordinates of two corresponding points in an ellipse and its… Illustration of an extension ladder. If ladder is leaned against a building, it will form a right triangle… Illustration of a ladder that is not perpendicular to the ground. If it is set on the ground and leaned… Illustration of a ladder that is not perpendicular to the ground. If it is set on the ground and leaned… Illustration of a ladder that is not perpendicular to the ground. If it is set on the ground and leaned… Illustration of a ladder that is not perpendicular to the ground. If it is set on the ground and leaned… ### Ladder Leaning Against a Building

Illustration of a ladder leaning against the side of a building (wall) to form a right triangle . ### Ladder Leaning Against a Tree

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a… ### Ladder Leaning Against a Tree

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a… ### Ladder Leaning Against a Tree

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a… ### Ladder Leaning Against a Tree

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a… ### 2 Ladders Leaning Against a Tree

Illustration of 2 ladders leaning against opposite sides of a palm tree to form similar right triangles.… ### 3 Ladders Leaning Against a Wall

Illustration of 3 ladders leaning against the side of a building (wall) to form right triangles. The… ### Lever and Fulcrum

Illustration of a lever with fulcrum F. W represents the weight lifted, P is the force that does the… ### Hammer Used as a Lever

Illustration of a hammer being used as a lever. F represents the fulcrum. ### Steel-yard Used as a Lever

Illustration of an ordinary steel-yard being used as a lever. F represents the fulcrum. Weight P is… ### Straight Lines to Find Ratios

Illustration of two straight lines that can be used to find ratios. ### Hydraulic Machine Exerting Pressure

Illustration of a hydraulic machine. "A principle known as Pascal's Law states that pressure exerted… ### 2 Rectangular Prisms

Illustration of 2 right rectangular prisms. The bases are congruent, but the height of the smaller prism… ### 2 Rectangular Prisms

Illustration of 2 right rectangular prisms. The bases are congruent, but the height of the smaller prism… ### Grooved Pulleys

These pulleys are grooved such as to guide the inner belt, in this system there is less of a chance… ### Leaning Tower

Illustration of a leaning tower with a perpendicular drawn from the top of the tower to the ground to… ### Palm Tree Perpendicular to Ground

Illustration of a palm tree that is perpendicular to the ground. The tree is perfectly straight, as… ### Wheel and Axle with Rope and Bucket

"...the mechanical advantage of this machine (wheel and axle) equal the ratio between the radii, diameters,…