Grade Levels: 3-5, 6-8

In this lesson plan adaptable for grades 3 through 8, students use BrainPOP resources (including an interactive game) to learn about basic geometry concepts. Students will explore angles, parallel lines, polygons, triangles, circles, and more while applying their findings to real-life situations.

Lesson Plan Common Core State Standards Alignments

Students will:

  1. Understand basic geometry concepts related to angles, parallel lines, polygons, triangles, and circles.
  2. Apply geometry understandings to real-life situations and virtual ones through online game play.


  • Internet and BrainPOP access
  • LCD projector/interactive whiteboard
  • Computers for students to use when playing the game in pairs
  • One protractor and level for each pair of students (optional)
  • Copies of the Graphic Organizer (optional)


angle; ray; degree; acute angle; right angle; obtuse angle; straight angle; line; parallel


Familiarize yourself with game play for A Tangled Web. In this math game, you control a tiny robotic spider named Itzi, who has fallen from the clock that is his home. He must climb back up the clock, finding a safe path through an intricate maze of tangled webs and solving cunning angle puzzles as he goes.

To start the game, click ‘Play’ and then ‘OK’, then '1' to start on level one, stage one. Your ultimate goal is to guide Itzi safely to the Warp Gate. You don’t control Itzi’s movement directly; instead, you rotate the giant cog and then Itzi ‘rolls’ according to gravity. Dotted around each level are blue Glo-Flies. Itzi must collect all the blue Glo-Flies to activate the Warp Gate--only then can he enter it and travel to the next level. Some special gold Glo-Flies are tucked away in hard-to-reach places, and they're worth big bonus points if you find them.

At certain points, Itzi’s path to the Gate will be blocked by a colored line. To remove the line, you must click on the angle puzzle of the same color and input its value: If the angle value is correct, the line disappears and Itzi can pass. If the angle value is incorrect, the line remains in place and Itzi loses energy. Itzi’s energy is shown by a bar in the top-left of the screen – if it runs out, you fail the level. You also fail the level if you don’t reach the Gate before time runs out. But don’t worry: you can always try again! Itzi also loses energy if he hits the cog rim or bumps into dangerous obstacles, such as Laser Walls and Spike Balls.

You can click "Help" at the beginning of game play and during game play to access this information.

Lesson Procedure:

  1. To build background knowledge, have students pair up and use the protractors and levels to measure the angles of several objects in the classroom. Have students use the Graphic Organizer to look for angles around the classroom.
  2. Play the Angles Movie for students. Turn on closed captioning to aid students in comprehension. You may wish to display the Review Quiz afterward and discuss the questions with students.
  3. Project the Do It tab of the Related Reading features (second tab from the left) and talk about angles in relation to clock hands. Challenge students to work in pairs to determine the angles for the clock hands shown.
  4. Tell students they will have the opportunity to practice and apply their understanding of angles and other geometric concepts through an interactive game featuring a spider and a clock. Project the game for the class to see.
  5. Show students how to get the A Tangled Web game started and model game play through a few rounds. When you start a new level, demonstrate how to spend a few moments spotting its main mathematical features. Are there any triangles that will be useful? Any parallel lines? Any circles that will help you with your calculations? Show students how to decide the best order in which to calculate the angles. Often you need to work out other angles in order to calculate the angles needed to remove lines. Make good use of the Notes function and encourage students to do the same when they play.
  6. Allow students to explore the game in pairs.
  7. Bring the group back to a whole-class discussion. Talk about some of the strategies students used. Guide them to understand that the more correct angle values you add, the easier it will be to work out the angles you need. Sometimes it helps to imagine extra lines in your diagram to solve problems. You will need to remove some lines more than once. Remind students that once they’ve correctly found an angle, they can remove its line as often as they wish. Sometimes it’s useful to rest Itzi against a line you can remove; then, when you remove it, Itzi will start rolling. Use this control to your advantage when timing is important. Ask students how the in-game math help assisted them. Have volunteers share shortcuts and tricks that saved time, and encourage them to take risks and try new strategies during game play.
  8. Review some of the math strategies used in the game. Remind students that if they can’t work out how to find an angle, they can use the in-game math help. You may want to ask volunteers to share information about angles and create a chart for students to reference. Record that angles making a straight line add up to 180°, angles meeting at a point add up to 360°, and angles in a triangle add up to 180°. In an isosceles triangle, two of the angles are equal. If you know one of the two equal angles, double it and then take the number you get away from 180° to find the other angle.
  9. Allow students to explore the game a second time, either independently or in pairs. Encourage them to reference the chart as they play.
  10. Use the Worksheet to assess what students have learned, or have them take the Quiz independently.

Extension Activities:

Use the movies and activities from our other Geometry and Measurement Unit to further students' understanding of the concepts in this game. More math games are available on GameUp.