Students use Ohio census data to solve problems, make comparisons, draw conclusions, and support predictions related to Ohio's population. They interpret and work with pictures, numbers and symbolic information.

Fifth graders explore angles by using protractors. They recognize, describe and determine the surface area and volume of three-dimensional shapes. Students recognize the right angle, acute angle, obtuse angle and vertex. They identify...

Ninth graders explain how wind can produce electricity. In this geometry lesson, 9th graders construct their own pin wheel turbine and calculate its power. They discuss the pros and cons of using wind generator.

Explains a simple pictorial way to remember basic reference angle values. Provides other memory aids for the values of trigonometric ratios for these "special" angle values, based on 30-60-90 triangles and 45-45-90 triangles.

Sharpen your logic, time, and angle recognition skills while working on this challenge. The solution is available to double check your results. (Hint: Use the "90 degree" right angle button on the clock to check if something is a right...

The formulas for 45-45-90 and 30-60-90 triangles and the use of the Pythagorean theorem to prove the formulas.

The formulas for 45-45-90 and 30-60-90 triangles and the use of the Pythagorean theorem to prove the formulas.

Use Paint Shop Pro to "Design a label for a drink of your choice." Learners will have the opportunity to explore the text tools that Paint Shop Pro offers to change the style, size, effects, and strength of the text.

In this activity, students will perform a series of experiments with inclined planes. They will learn that as the angle of inclination of the inclined plane approaches 90 degrees, the value of the acceleration of the cart traveling down...

Generalize that a tangent and a radius form a 90-degree angle.

In Spanish. Learn how to calculate trigonometric ratios of angles greater than 90 degrees.

Young scholars learn about the engineering design process as they design, build, test, and evaluate a conveyor system made with everyday items than can move pieces of candy 4 feet including a 90 degree turn. The objective of the lesson...

Illustrated examples and interactive practice problems that introduce students to the concept of the critical angle, the angle of incidence that provides an angle of refraction of 90-degrees.

Explains how simple polygons translate into matrices and how to use 2x2 matrices to represent transformations in a plane. Includes video demonstrating an example where a vector must be rotated 90 degrees using matrices. [4:18]

Explains how to model angles in the x,y-plane, and demonstrates how to extend the concept of trig ratios to angles larger than 90 degrees.

This very basic website gives a clear, simple explanation of what a right angle is.

This very basic website gives a clear, simple explanation of what an acute angle is.

Looking for a 10-minute review of the major concepts of trigonometry? This site is a quick recap of degrees and radians, SOH CAH TOA, Pythagorean identities, and special right triangles are all found here.

Get a visual and animated definition of what an acute angle is, as well as examples of acute angles in the real world.

[Free Registration/Login Required] Students explore the concept of perpendicular lines by navigating through the interactive learning module and then answering questions that go along with the module. Students can also learn more about...

Three trig tables are provided for student and teacher reference. The first table lists the sine, cosine, tangent, secant, cosecant, and cotangent values of all whole-number angles from 0 to 90. The radian equivalent (to four decimals)...

[Free Registration/Login Required] This flipchart is designed to introduce the student to the concept of the right angle and to give the student practice in identifying right angles as well as measuring angles with a protractor.

Learn about right angles with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.

A map from 1898 showing the Standard Time Belts in the contiguous 48 states as they were then established. "The main body of our country is so broad from east to west that more than three hours are required for rotation to carry it past...