##
* *Reflection: Rigor
iPhone, iSpy: Cell Phone Triangulation - Section 4: Elaborate

Please note that this activity is designed for much older students in a high school math classroom. The objective, as it is designed, is to apply the Law of Sines and Cosines to determine angles and distances in triangles. Sines and Cosines are mentioned in the activities, and students will immediately question their meaning, as they have not yet covered this in math class. It is suggested to discuss this activity with your math teacher to see if s/he can provide support with the geometry concepts addressed. However, it is NOT necessary to discuss the Laws of Sines and Cosines in order to be successful. By providing a little front loading on angle relationships in triangles, as well as area/perimeter of triangles this is all that would be needed to be successful with this lesson.

While some students will get the math behind the activity and will be able to complete this independently, many will need modeling and/or support throughout the entire activity, which I gladly provide. My goal is for students to experience and understand forensic science processes, and not to necessarily get the math at this time. It's definitely an added bonus if they do, but it is not a requirement.

This activity addresses both 6th and 7th grade Common Core geometry standards:

*CCSS.Math.Content.6.G.A.1**Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.*

*CCSS.Math.Content.7.G.B.5**Use facts about supplementary, complementary, vertical, and adjacent angles in a multi-step problem to write and solve simple equations for an unknown angle in a figure.*

*Math Activity*

*Rigor: Math Activity*

# iPhone, iSpy: Cell Phone Triangulation

Lesson 13 of 15

## Objective: SWBAT understand how triangulation can be used to track cell phone location.

#### Engage

*5 min*

**Please watch the video below before attempting this lesson!**

I start each class period in this unit with a warm-up activity that targets forensic science concepts and other skills (observation, problem-solving, etc.) Not only does this get the students in the frame of mind necessary to address the field of forensics, but it also introduces key vocabulary they will use throughout the unit in a more relevant way. In addition, this activity allows students to refine their research skills as they perform quick internet searches to find the correct answers. By using the attached weekly Answer Sheet* and passing it out as they enter the classroom every Monday morning, not only can I save paper, but I can also provide a routine that allows students to begin without prompting, waiting for paper, or asking things such as, "What do we do?" and, "Where do we write our answers?"

For this particular lesson, I have decided to utilize a Video Challenge entitled, Forensic Entomology*, in which students watch a short video clip about forensics and follow up by answering an assortment of trivia questions.

After providing about 2-3 minutes to choose the correct answers, we go over them together and discuss the information provided. I help students to define key terms and providing background knowledge necessary to help students understand the questions. However, I do not spend as extended period of time on this portion, as it is just meant to be an activator and not necessary to understanding the core of the lesson at this time.

**Challenges and answer sheet courtesy of http://sciencespot.net/Pages/classforscistarters.html*

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#### Explore

*10 min*

I start this portion of the lesson by asking students to raise their hand if they have a cell phone. Most to all students at this age do carry a phone. If many do not, then I ask them to raise their hand if their parents own a cell phone. By this time, the whole class has their hand raised. I ask them to turn and talk about all the ways cell phones can be an important piece of evidence when investigating a crime.

After giving a few minutes to discuss, I call on random students to share one of the ideas that they talked about with their partner/s. Many come up with some creative (and perhaps nonsensical) ways that cell phones can be used in crime investigation.

Next, I have the students view the video, "Cell Phone Tracing leads to Crucial Evidence".

After watching, I challenge students to determine exactly how cell phones can be tracked, having them turn and talk again.

*expand content*

#### Explain

*20 min*

Next, I write the word "triangulation" on the board and tell students that investigators use triangulation to track cell phone locations. I ask the students if they can find any root words in the word on the board that will help them determine the meaning of the entire word. Students usually identify angle or triangle, and I challenge them to think about what angles or triangles might have to do with cellphone tracking. I ask them them to write down their ideas before we move on.

Next, I have students form pairs and pass out the two articles about cell phone triangulation - Cell Phone Triangulation and Cell Phone Tower Triangulation. I instruct the students to partner read the two articles, stopping to provide a brief oral summary after each partner take a turn reading.

After reading, I have them add to what they originally wrote, explaining the meaning of triangulation and how it can be used to track a cell phone, as well as how it might be used to help solve a crime.

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#### Elaborate

*30 min*

Now that students have an understanding of what triangulation is and how it is used to determine location, it is time to practice a few examples. I pass out the Cell Phone Triangulation Activity*, provided by 21st Century Math Projects. Because of the advanced level of math *presented in this activity, I allow students to choose between completing individually, with a partner or small group, or with my guidance. Students who choose to work without my guidance move to the back and/or sides of the classroom, while students who choose to work with me stay in the front so that I can model problems on the board.

After completing the activity, we discuss how triangulation works and why this would be valuable in the field of forensics. Next, I pass out a few local newspapers from the past month and challenge students (in pairs) to find crime stories in which triangulation was used or may have been used to find a suspect or victim. As students find stories that relate to our learning topic, I have them share quotes or sections from the article that support their thinking.

**Please see my reflection for more information on this activity.*

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#### Evaluate

*15 min*

Students have now learned about what triangulation is and how it is used in an investigation. They have also practiced a few examples for themselves. As a final assessment, I want to see if they can apply their learning about triangulation and other forensic processes to the scenario of a crime scene. Students demonstrate their understanding by completing the attached exit ticket prior to leaving class.

#### Resources

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I noticed that you have a math cell phone triangulation activity. The math content addressed in this activity (law of sines and cosines) is honors geometry content (10th grade), sometimes even taught in Precalculus (12th grade).

| 10 months ago | Reply##### Similar Lessons

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- LESSON 1: What is Forensic Science?
- LESSON 2: Real Life Forensics vs. Media Hype
- LESSON 3: The "Eyes" Have It: Analyzing Eyewitness Testimony
- LESSON 4: Handwriting Analysis
- LESSON 5: Caught Red-Handed: Fingerprint Analysis
- LESSON 6: A Good Source of Fiber: Fiber Analysis
- LESSON 7: Bad Hair Day: Hair Analysis
- LESSON 8: Written in Bone: Forensic Anthropology (5 Day Mini-research Project)
- LESSON 9: Say Cheese: Dental Analysis
- LESSON 10: DNA Analysis
- LESSON 11: Read My Lips: Lip Print Analysis
- LESSON 12: Nothing But The Truth: Lie Detection
- LESSON 13: iPhone, iSpy: Cell Phone Triangulation
- LESSON 14: Tour a Crime Lab
- LESSON 15: Bloodstain Analysis