An interactive applet and associated web page that demonstrate obtuse angles (those between 90 and 180 deg). The applet presents an angle (initially obtuse) that the user can adjust by dragging the end points of the line segments forming the angle. As it changes it shows the angle measure and a message that indicate which type of angle it is. There a software 'detents' that make it easy capture exact angles such as 90 degrees and 180 degrees The message and angle measures can be turned off to facilitate classroom discussion. The text on the page has links to other pages defining each angle type in depth. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that demonstrate the three types of triangle: acute, obtuse and right. The applet shows a triangle that is initially obtuse (one angle greater than 90 degrees) which the user can reshape by dragging any vertex. There is a message changes in real time while the triangle is being dragged that tells if the triangle is an acute, right or obtuse triangle and gives the reason why. By experimenting with the triangle student can develop an intuitive sense of the difference between these three classes of triangle. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

The lesson begins by introducing Olympics as the unit theme. The purpose of this lesson is to introduce students to the techniques of engineering problem solving. Specific techniques covered in the lesson include brainstorming and the engineering design process. The importance of thinking out of the box is also stressed to show that while some tasks seem impossible, they can be done. This introduction includes a discussion of the engineering required to build grand, often complex, Olympic event centers.

This lesson unit is intended to help sixth grade teachers assess how well students are able to: Analyze a realistic situation mathematically; construct sight lines to decide which areas of a room are visible or hidden from a camera; find and compare areas of triangles and quadrilaterals; and calculate and compare percentages and/or fractions of areas.

This lesson allows students to build fluency with shapes by identifying them in in the outdoor classroom.

This challenging problem and brainteaser gives students an opportunity to compose and decompose polygons to make rectangles.

This short video and interactive assessment activity is designed to give fourth graders an overview of ellipses, trapezoids, rhombi, and polygons.

This short video and interactive assessment activity is designed to give fifth graders an overview of forming figures with cutouts.

This lesson plan uses Ozobots and their color code commands coding to review Geometry concepts.

The purpose of this 3 ACT task is to provide students with an opportunity to problem solve based on a real-world situation. In the task, students are presented with a map of a Bull Kelp bed near Squaxin Island and asked to generate their own questions that could be answered using the map. Students then decide on necessary resources for finding the solution and are given time as a group to complete their work. The task concludes by having students examine the information provided in Act three to see if it answers their question. Includes slides to support the implementation of "Keeping An Eye On Kelp (Algebra)" Math Performance Task with charts, images, etc.

The purpose of this task is to provide students an opportunity to use mathematics addressed in different standards in the same problem.

This resource was created by Jill Anderson, in collaboration with Dawn DeTurk, Hannah Blomstedt, and Julie Albrecht, as part of ESU2's Integrating the Arts project. This project is a four year initiative focused on integrating arts into the core curriculum through teacher education, practice, and coaching.

This high level task is an example of applying geometric methods to solve design problems and satisfy physical constraints. This task is accessible to all students. In this task, a typographic grid system serves as the background for a standard paper clip.

Students learn about parallax in this Moveable Museum unit, in which they use mathematical techniques related to parallax to calculate the height of an object. The eight-page PDF guide includes suggested general background readings for educators, activity notes, step-by-step directions, a Data Sheet and a Tangent Table, and an astrolabe template.

Students act as civil engineers developing safe railways as a way to strengthen their understanding of parallel and intersecting lines. Using pieces of yarn to visually represent line segments, students lay down "train tracks" on a carpeted floor, and make guesses as to whether these segments are arranged in parallel or non-parallel fashion. Students then test their tracks by running two LEGO® MINDSTORMS® NXT robots to observe the consequences of their track designs, and make safety improvements. Robots on intersecting courses face imminent collision, while robots on parallel courses travel safely.

STUDENT ACTIVITY - 4th - TXThis is a distance-learning lesson students can complete at home. The student will use their knowledge of parallel and perpendicular lines to compare those that are man-made and others found in nature. This activity was created by Out Teach (out-teach.org), a nonprofit providing outdoor experiential learning to transform Science education for students in under-served communities.

Students will use their knowledge of parallel and perpendicular lines to compare those that are manmade and others found in nature

A web page and interactive applet showing the definition and properties of a parallelogram. The applet shows a parallelogram where the user can drag any vertex. The other points then move in such a way that the figure remains a parallelogram at all times. A control to hide the details allows a classroom discussion where students can try to infer what the properties are as it is reshaped by the discussion leader. Text on the page has the formal definition and properties of the parallelogram with links to related pages. A companion page is http://www.mathopenref.com/parallelogramarea.html showing the ways to calculate the area of a parallelogram Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

This short video and interactive assessment activity is designed to teach third graders about fraction of a whole.