Explains the properties of acute, right, and obtuse angles. [5:33]

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.

The three types of angles, right, acute, and obtuse, exist in our everyday surroundings. Students find these angles using classroom items.

Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology includes rich features that engage students in scientific inquiry, highlight careers in the biological sciences, and offer everyday applications. The book also includes various types of practice and homework questions that help students understand—and apply—key concepts. The 2nd edition has been revised to incorporate clearer, more current, and more dynamic explanations, while maintaining the same organization as the first edition. Art and illustrations have been substantially improved, and the textbook features additional assessments and related resources.

By the end of this section, you will be able to do the following:

List the steps of replication and explain what occurs at each step
Describe the lytic and lysogenic cycles of virus replication
Explain the transmission of plant and animal viruses
Discuss some of the diseases caused by plant and animal viruses
Discuss the economic impact of plant and animal viruses

Students learn about common geometry tools and then learn to use protractors (and Miras, if available) to create and measure angles and reflections. The lesson begins with a recap of the history and modern-day use of protractors, compasses and mirrors. After seeing some class practice problems and completing a set of worksheet-prompted problems, students share their methods and work. Through the lesson, students gain an awareness of the pervasive use of angles, and these tools, for design purposes related to engineering and everyday uses. This lesson prepares students to conduct the associated activity in which they “solve the holes” for hole-in-one multiple-banked angle solutions, make their own one-hole mini-golf courses with their own geometry-based problems and solutions, and then compare their “on paper” solutions to real-world results.

A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.

Students will learn how to apply the properties and characteristics of all triangles to solve real-world problems and identify and use the unique characteristics of right, isosceles, equilateral, acute, obtuse, and scalene triangles.

Take a look at this tutorial and learn about some of the different kinds of triangles. [4:25]

This site from WebMD Health contains great information on Hepatitis A. Several pictures are provided along with information on topics such as: Causes, symptoms, risks, exams and tests, treatment, prevention and surgery.

This site from WebMD Health contains great information on the various forms of hepatitis, including hepatitis A, hepatitis B, hepatitis C, D and E. Also includes information on diagnostic and test procedures as well.

Drinking water comes from many different sources, including surface water and groundwater. Environmental engineers analyze the physical properties of groundwater to predict how and where surface contaminants will travel. In this lesson, students will learn about several possible scenarios of contamination to drinking water. They will analyze the movement of example contaminants through groundwater such as environmental engineers must do (i.e., engineers identify and analyze existing contamination of water sources in order to produce high quality drinking water for consumers).