Solve two challenging problems that apply the inscribed angle theorem to find an arc measure or an arc length.

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Solve three challenging problems that apply properties of inscribed shapes to find an arc length or a missing angle.

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Solve two challenging problems that apply properties of tangents to find the radius of a circle with a tangent.

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Explore real-life and animated views illustrating the daily patterns of motion of the Sun, Moon, and stars in the sky. Students engage with a variety of media such as an interactive storybook, time-lapse videos, and images to identify evidence of motion and predict future appearances of the Sun, Moon, and stars. Support materials include: Handouts and Teaching Tips

Observe the effect of Earth's tilt on the amount of daylight that occurs in the northern and southern hemispheres with these videos and diagrams. This resource provides opportunities for students to observe, ask questions, and construct explanations about cyclical patterns, such as differences in the duration of daylight in summer and winter and Earth's rotation [6:46] Support materials are provided.

Observe how the Sun appears to rise in one side of the sky and set in the opposite side in this media gallery from GBH. Use the four time-lapse videos in this media gallery to observe the apparent motion of the Sun over a day and the images in the gallery to compare changes in the apparent motion of the Sun across the sky throughout the day.

Students examine what Anne Frank's writing and a video dramatization of her diary reveal about her character and how it changed while she was in hiding.

This lesson focuses on the character of Scout Finch from the novel To Kill a Mockingbird by Harper Lee. It includes excerpts from the American Masters documentary entitled Harper Lee: Hey, Boo, discussion questions, teaching tips, and links to a full teaching guide for To Kill a Mockingbird more video clips and information about Harper Lee's life.

This video segment adapted from NASA describes the basic characteristics of our star, the Sun. Includes background reading material and discussion questions. Video length: 1 min. 28 sec.

Did you know we can credit Charlemagne with the invention of the question mark? During the reign of Charlemagne, there was a revival of classical learning. Charlemagne knew he had to rebuild Europe and bring stability to the region. He accomplished this through religion and education. Watch this video to see details about these accomplishments and more. [11:34]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This interesting site has a variety of activities and games to use in the classroom or at home to teach letter recognition, phonics, and beginning writing skills. Learn about individual letters at the Alphabet Soup Cafe, create an Alphabet Scrapbook, learn to write the letters with Spinner the Spider, and learn about alphabet fonts in the section on Shapes and Features.

Students experience the information aftermath of a fictional event as it unfolds on social media. They also learn about five common logical fallacies, then evaluate the evidence in several arguments. A free educator account is necessary to assign this Checkology lesson.

Discover how to make sense of the health and wellness information vying for our attention — and avoid being misled. A free educator account is necessary to assign this Checkology lesson.

Test your news judgment by selecting the most newsworthy stories to feature on the homepage of your news site, then explain your choices. A free educator account is necessary to assign this Checkology lesson.

Learn the relationship among advertisers, the news media and the public to understand the rise of branded content and debate the ethical implications of new forms of marketing. A free educator account is necessary to assign this Checkology lesson.

Learn the ways that ordinary people can document and expose wrongdoing, including monitoring news coverage for breaches of journalism standards, by examining a series of case studies. A free educator account is necessary to assign this Checkology lesson.

Learn to recognize conspiracy theories and explain what makes people vulnerable to conspiratorial thinking. A free educator account is necessary to assign this Checkology lesson.

Learn about the historic watchdog role that a free press has played in the U.S. by exploring a collection of investigative reports spanning more than a century. A free educator account is necessary to assign this Checkology lesson.