## Systems of Linear Inequalities: Paleontological Dig

(Editor’s note: the original post and activity mistook Paleontology for Archaeology. Archaeology is the study of human made fossils; paleontology is the study of dinosaur remains. The terminology has since been corrected and updated. Thanks to the commenters for the newfound knowledge.)

Here’s an activity on systems of inequalities that teaches or reinforces the following concepts:

• Systems of Linear Equations
• Linear Inequalities
• Systems of Linear Inequalities
• Properties of Parallel and Perpendicular Slopes (depending on the equations chosen)

In this task students are asked to design four equations that would “box in” skeletons, as in a paleontological dig.

DOC version: (paleo-dig)

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Facilitation

• Give students the entry event and instructions. Have one student read through it aloud while others follow along.
• Consider getting started on the first one (Unicorn) as a class. Should our goal be to make a really large enclosed area or a smaller one?
• Students may wish to start by sketching the equations first, others may chose to identify crucial points. Answers will vary.
• If you have access to technology, you may wish to have students work on this is Desmos. Personally, I prefer pencil and paper. Here’s the blank graph in Desmos:  https://www.desmos.com/calculator/y1qkrfnsw2
• For students struggling with various aspects of the problem , consider hosting a workshop on the following:
• Creating an equation given a line on a graph
• Finding a solution to a system of equations
• Sensemaking:
• Did students use parallel and perpendicular lines? If so, consider bubbling that up to discuss slopes.
• Who thinks they have the smallest area enclosed? What makes them think that? Is there any way we can find out?
• Let’s say we wanted to represent the enclosed area. We would use a system of linear inequalities. Function notation might be helpful here:
• f(x) < y < g(x) and h(x) < y < j(x) (special thanks to Dan for helping me figure this notation out in Desmos!) === Paleontological Dig ===

Congratulations! You’ve been assigned to an paleontological dig to dig up three ancient skeletons. Thanks to our fancy paleontology dig equipment, we’ve been able to map out where the skeletons are.

Your Task: For each skeleton, sketch and write four linear functions that would surround the skeleton, so we may then excavate it. 