Lesson Title: Triangles

Unit: Geometry

Grade Level: 7th or 8th grade

Estimated time requirement: 8 Days of regular 45 minute class periods

Summary (25-50 words): Study the properties of different triangles based on their sides and angles.  Study the effects of proportional changes in triangles.  Students will present their understanding of triangles to the class in a PowerPoint presentation on the last day of the study.

 

 

Objectives:

  • Introduce equilateral, scalene and isosceles triangles.
  • Introduce equiangular, acute, obtuse and right triangles.
  • Estimate the area of different triangles drawn on graph paper by plotting points. Then find the area of the same triangle by using a formula.
  • Generate similar triangles by dilations and reductions. Compare area of dilations and reductions to original triangles.
  •  Learn the process for calculating the missing side of a right triangle by using the Pythagorean Theorem.
  • Use measuring devices to verify the calculated measure of a side of a right triangle.
  • Create right triangles out of paper, cardboard and other materials.
  • Use the Internet to find examples of triangles in architecture.
  • Create PowerPoint Presentations about triangles.
  • Burn a CD to save the presentations.
  • Use the laptop and projector to present PowerPoint to the class and to parents on parent night.
  • Tape the presentations with the video camera.

Content Standards:

 

http://www.tea.state.tx.us/rules/tac/chapter111/ch111b.html

http://www.tea.state.tx.us/rules/tac/chapter123/index.html

 

Math TEK 7.6B, 7.9, Solve For Area, 8.6A, 8.6B,8.7B,8.7C, 8.8C, 8.9A

Technology TEK 2.A,C  6.B,C

Assessment:

  • Area of Triangles Worksheet, Proportional Triangles Worksheet, Rubric for PowerPoint Presentations, Right Triangles Worksheet, Evaluate WebQuest by standards given on WebSite.

 

Materials:

  • Tape measures and/or rulers computers
  • Computers
  • Calculators
  • Pencils
  • Graph Paper
  • Paper
  • TAKS Formula chart
  • Internet Access
  • Video Camera
  • Digital Camera

Resources:

 

Algebra WebQuest

http://allabery.com/courses/webquest/wilkins/index.html

other resources for PowerPoint presentations

http://www.mathsnet.net/shape/index.html

http://shodor.org/interactivate/activities/pyth/

http://nlvm.usu.edu/en/nav/category_g_2_t_3.html

http://www.ies.co.jp/math/java/geo/congruent.html

http://www.321know.com/geo.htm

http://www.earthmeasure.com/index_earth.html (Cultural Connections)

http://www.figurethis.org/fc/family_corner.htm (Family Connections)

 

 

Prior Knowledge/Skills: How to read a ruler or tape measure in centimeters and inches, how to plot points on a Cartesian coordinate system, how to gain internet access and “surf” the web for information, how to create a PowerPoint presentation.

Procedures:

  • Day 1: View video clip and the triangle PowerPoint presentation as an introduction to the 5 day unit. Discuss the presentation. Discuss vocabulary associated with triangles. The student is expected to sketch a coordinate system on graph paper, then draw triangles on the graph paper. The student then is expected to estimate the area of the triangles graphed by counting the squares inside the triangle. Then the area will be calculated by using the formula for area of triangles. Area of Triangles Worksheet and ten pieces of graph paper.
  • Day 2: Pass out Proportional Triangles Worksheet. The students is expected to learn what a dilation and reduction does to the area of a triangle. This will be done by means of graphing on a coordinate system and by formula. Pass out the example of a dilation and go over it with the class.  Use the document camera to show examples. Then pass out 3 sheets of graph paper to graph the dilations and reductions. The student is graded on the graphing as well as the answers to the questions on the worksheet with the example. 
  • Day 3: .View PowerPoint presentation on finding the missing side of a right triangle. The student is expected to then calculate missing sides of right triangles using a calculator.  Right Triangles Worksheet. Students are expected to generate a rubric for grading the PowerPoints. The only field I require is that they have at least 5 slides (Overall Format on provided rubric). The other areas will be chosen by them from a list of topics.

Day 4: Go to the Internet Lab. Students use the Internet lab to research Right Triangles.  Using the link (http://allabery.com/courses/webquest/wilkins/index.html) students complete a math WebQuest.

             Students spend thirty minutes collaborating with the instructor using the LCD projector to brainstorm how to utilize classroom and technology tools instead of traditional methods mentioned in the WebQuest.  The brainstorming and WebQuest activity should take three to four days. Day 1 & 2 Web Quest. Find examples of Tuscan Architecture. Design a gate to go with a Tuscan style house. The WebQuest is designed for 20 minutes for five days but may be condensed into three days for 45 minute periods.  Students need paper, pencil and a calculator. Students may save any information to their individual files located on a local server.

  • Day 5:  Work on what is labeled Day 3 & 4  of  WebQuest. Students continue work on WebQuest and save their results to the teacher’s jumpdrive for transportation back to the classroom or use network folders. On Microsoft Word using the drawing tools, represent the gate that has been designed. The “Paint” program may also be used.
  • Day 6: Day 5 WebQuest-The students are expected to write a paragraph on the importance of the Pythagorean Theorem and right triangles in architectural design. The paragraph must then be typed on the computer using Microsoft Word and printed to turn in.
  • Day 7:  The students are expected to work on the PowerPoint presentations. The students, in pairs, are to create a PowerPoint describing all that they have learned about triangles.  Coordinate with the computer teacher to allow the students to work on the PowerPoints in computer class also. Students are expected to save the presentation on a CD to make the presentation portable.
  • Day 8: The students are expected to present the PowerPoint projects that were created yesterday. One of the partners will film using the video camera and the other will present. Students are to present the PowerPoint presentations to parents in the evening. Invitations to parents will go home with student.

 

 

 

 

Modifications:

·                                Peer assistance with internet

·                                Peer assistance with measuring.

·                                Calculators

·                                Inclusion teacher or aide

Technology Infusion:

  • Internet Lab
  • PowerPoint
  • Video Camera
  • Digital Camera
  • Calculators

 

Cultural Connections: right triangles in Tuscan architecture, designing an evaluation tool (rubric)

 

 

Family Connection: Present PowerPoints to parents in the evening of the last day. Invitations went home with students on last day of work in the classroom.