Author: Kate Poirier (Page 1 of 2)

Week 11 checklist

April 21, 2025 / Kate Poirier / 0 Comments

Monday, April 21 to Sunday, April 27

Lessons

Platonic solids (part 3)
- Geogebra 1 (nets)
- Geogebra 2 (duality: hexahedron and octahedron)
- Geogebra 3 (duality: dodecahedron and icosahedron)
Nets and surface area for polyhedra and other solids

Homework

Homework #7 will be assigned later
Make an appointment to prepare for your in-class presentation

Other

Test #2 will be given in class next Monday, April 28. It will cover all 3D Euclidean geometry topics.
See info about Pythagorean Theorem projects here

Project #1 grades & feedback

April 17, 2025 / Kate Poirier / 0 Comments

Thanks for your patience with waiting for feedback on your Pythagorean theorem project. You all did a lot of good work! Grades for the GeoGebra component and Video Lesson component are now in Brightspace and feedback is given as comments on your project posts.

As I’ve mentioned in class, with this project, students in my previous classes have needed to re-do their GeoGebra component (or sometimes the whole project) if the GeoGebra file does not pass the drag test. This is the situation for a few groups in your class too. To pass the drag test, a user needs to … Read More

Week 10 checklist

April 7, 2025 / Kate Poirier / 0 Comments

Monday, April 7 to Sunday, April 13

Lesson

Platonic solids (K2 2.3 & 2.5)
- Links for in class:
  - Geogebra 1 (nets)
  - Geogebra 2 (duality: hexahedron and octahedron)
  - Geogebra 3 (duality: dodecahedron and icosahedron)
- Bonus: article on higher-dimensional Platonic solids (here)

Homework

Homework #6: hard copy due in class Wednesday, April 9
In-class presentations: topic choice due by Wednesday, April 9

Other

Spring break is next week. Homework #7 will be assigned later. You should spend your time working on:
- preparing your in-class presentation (instructions)
- (optional) preparing for your test #1 corrections interview (information)

Homework #6

April 3, 2025 / Kate Poirier / 0 Comments

Hard copy due in class Wednesday, April 9

See homework guidelines and tips here

Consider an equilateral triangle in a plane with side length $s$ . Assume that this equilateral triangle is a base of a right triangular prism with height $h$ .
1. Use the integration formula from class to derive the formula for the volume of this right triangular prism with equilateral base.
2. Use your formula to calculate the volume of a right triangular prism with equilateral base of side length 2 and height 3.
Consider an equilateral triangle in a plane with side length $s$ . Assume that this equilateral triangle

In-class presentations

March 31, 2025 / Kate Poirier / 11 Comments

Part 0 due Wednesday, April 9

For your in-class presentation, you will be presenting one of the following topics (most are from Venema’s book; material corresponding to presentations 9 and 10 will be shared with the presenters).

Date	Topic
4/30	1. The Classical Triangle Centers (V2.1-2.4) 2. Circumscribed, Inscribed, and Escribed Circles (V4.1-4.3)
5/5	3. The Medial and Orthic Triangles (V5.1-5.3) 4. The Nine-Point Circle (V7.1-7.2)
5/7	5. Ceva’s Theorem Part 1 (V8.1, 8.2, 8.5) 6. Ceva’s Theorem Part 2 (V8.3: proof)
5/12	7. Theorem of Menelaus (V9.1-9.2–skip trigonometric) 8. Desargue’s Theorem (V11.2)
5/14	9. Introduction to spherical geometry (including

Week 9 checklist

March 31, 2025 / Kate Poirier / 0 Comments

Monday, March 31 to Sunday, April 6

Monday, March 31 is a holiday. Eid Mubarak!

Lesson (Wednesday, April 2)

Volumes of 3-dimensional solids: prisms, pyramids, cylinders, cones, ball (K2 2.1 & 2.2; 3.1 & 3.2)

Homework

Homework #5 hard copy due in class Wednesday, April 2
Homework #6 hard copy due in class Wednesday, April 9

Other

Test #1 corrections and presentation preparation sign-up sheet
In class presentations (first deadline: Wednesday, April 9)

Homework #5

March 27, 2025 / Kate Poirier / 0 Comments

Hard copy due in class Wednesday, April 2

See homework guidelines and tips here

Hint for Problems 1-4: you should rely on the definitions of the relevant objects for each problem as given in class.

Consider a configuration of two lines in 3-space. We have seen two situations where a plane can pass through these two lines. Describe each of these two possible situations (what must the two lines satisfy in order for a plane to pass through them). Be precise and include all details. Then describe a third situation where two lines are configured in such a way that

Week 8 checklist

March 23, 2025 / Kate Poirier / 0 Comments

Monday, March 24 to Sunday, March 30

Lessons

Lines and planes (K2 Ch 1)
Parallelepipeds and pyramids & Volumes of prisms and pyramids (K2 2.1 & 2.2)

Homework

Homework #5 hard copy due in class Wednesday, April 2

Other

Please fill out the grading policy survey by Wednesday, March 26
Office hours Monday, March 24 start at 1:45pm
Office hours Wednesday, March 26 are half cancelled (I will be on a Zoom call in my office; you may interrupt if there’s something that can’t wait)
No classes are scheduled for next Monday, March 31 (see you on Wednesday)

Week 7 checklist

March 16, 2025 / Kate Poirier / 0 Comments

Monday, March 17 to Sunday, March 23

Monday, March 17

Test #1 in class

Wednesday, March 19

Basic straightedge/compass constructions
Check out Euclid the Game (you may like to bring a device you can play this on to Wednesday’s class)

Week 6 checklist

March 10, 2025 / Kate Poirier / 0 Comments

Monday, March 10 to Sunday, March 16

Lessons

Conic sections
- See this Geogebra applet for an introduction to conic sections
- See these Geogebra applets for more details (not all are relevant for our class)
- See these worksheets for extra examples

Homework

Homework #4 hardcopy due in class Wednesday, March 12
No homework due next week; Test #1 instead

Other

Test #1 will be given in class on Monday, March 17. It will cover all topics from Unit 1 (2-dimensional Euclidean geometry) except for basic constructions.

Homework #4

March 5, 2025 / Kate Poirier / 0 Comments

Hard copy due in class Wednesday, March 12

See homework guidelines and tips here

Let that the square $◻ A B C D$ be similar to the square $◻ A^{'} B^{'} C^{'} D^{'}$ with a proportionality constant $λ = \frac{5}{2}$ (when going from $◻ A B C D$ to $◻ A^{'} B^{'} C^{'} D^{'}$ ). Assume that $| \overset{―}{A B} | = x + 3$ and $| \overset{―}{A^{'} B^{'}} | = 3 x + 5$ . Determine the perimeter of $◻ A B C D$ . (Your answer should be a number.)
Consider two intersecting chords in a circle. The intersection point cuts one chord into two pieces: one of length $a$ and one of length $b$ . The intersection point cuts the other

Week 5 checklist

March 3, 2025 / Kate Poirier / 0 Comments

Monday, March 3 to Sunday, March 9

Schedule

Thursday, March 6 follows a Wednesday schedule, so we’ll see each other Monday, Wednesday, and Thursday

Lessons

Circles and inscribed angles
Transformations in the coordinate plane
- Try out this game
Basic constructions (if time)
- Try out this game

Homework

Homework #3 hard copy due in class Wednesday, March 5
Homework #4 hard copy due in class Wednesday, March 12

Other

Test #1
- In class Monday, March 17
- Covers everything from Unit 1 on the schedule (the schedule is still out of date, but the topics are listed in the correct order)
- Start

Homework #3

February 26, 2025 / Kate Poirier / 2 Comments

Hard copy due in class Wednesday, March 5

See homework guidelines and tips here

Venema 0.9.2 (page 10)
Prove that the diagonals of any rhombus are perpendicular to each other.
Let the lengths of the diagonals of a rhombus be $d_{1}$ and $d_{2}$ . Prove that the area of this rhombus is $A = \frac{1}{2} d_{1} d_{2}$ .
Prove that the diagonals of any isosceles trapezoid are congruent.
Prove that the sum of the measures of the exterior angles of any polygon is $360^{\circ}$ .

Week 4 checklist

February 24, 2025 / Kate Poirier / 0 Comments

Monday, February 24 to Sunday, March 2

Lessons (may be adjusted)

Polygons (K1 1.4)

Homework

Homework #2 hard copy due in class Wednesday, February 26
Project #1 Parts 2 & 3 due on the OpenLab by Sunday, March 2 (extension)
Homework #3 hard copy due in class Wednesday, March 5

Schedule

Next week, Thursday, March 6 follows a Wednesday schedule, so we’ll see each other Monday, Wednesday, and Thursday
According to our original schedule, Test #1 was planned for Thursday, March 6. The test will be postponed until we finish all of the content in Unit 1.

Homework #2

February 18, 2025 / Kate Poirier / 2 Comments

Hard copy due in class Wednesday, February 26

See homework guidelines and tips here

Triangles $△ A B C$ and $△ D E F$ are similar. Lengths $A B = 4$ , $B C = 2$ , $A C = 5$ , and $D E = 6$ . Find the lengths $E F$ and $D F$ .
Consider two parallel lines that are intersected by a transversal, forming eight angles. Assume that one of the eight angles is $42^{\circ}$ . Find the measures of the other seven angles.
Consider two supplementary angles. Prove that the bisectors of these angles are perpendicular to each other.
Consider the bisector of one of the exterior angles of a triangle.

Week 3 checklist

February 18, 2025 / Kate Poirier / 0 Comments

Monday, February 17 to Sunday, February 23

Schedule

Monday, February 17 is a holiday (no class)
Tuesday, February 18 follows a Monday schedule, so we meet on Tuesday and Wednesday this week

Lessons

Similar triangles (part 2)
Quadrilaterals
Polygons

Homework and deadlines

Homework #1 hard copy due in class Wednesday, February 19
Project #1
- Part 1 due on the OpenLab Wednesday, February 19
- Parts 2 & 3 due on the OpenLab Wednesday, February 26
Homework #2 hard copy due in class Wednesday, February 26

Project 1 – Pythagorean theorem proofs

February 10, 2025 / Kate Poirier / 6 Comments

Part 0 due ASAP

Part 1 due Wednesday, February 19

Parts 2 & 3 due ~~Wednesday, February 26~~ Sunday, March 2

Introduction

The Pythagorean theorem—the square of the hypotenuse of a right triangle is equal to the sum of the squares of the two other sides—is arguably the most famous mathematical result. While many people remember the statement of the theorem from high school, way fewer people know a proof…and even fewer know that there are literally hundreds of proofs!

Summary

For this project, you and your team will:

choose one of the proofs of the Pythagorean theorem to learn,

Week 2 checklist

February 10, 2025 / Kate Poirier / 0 Comments

Monday, February 10 to Sunday, February 16

Lesson

Perpendicular lines and parallel lines (part 2) (V 0.6)
Similar Triangles (V 0.8)

Homework

Homework #1 due in class Wednesday, February 19
Project #1
- Part 0 due ASAP
- Part 1 due Wednesday, February 19
- Parts 2 & 3 due Wednesday, February 26
Homework #2 will be posted next week, due in class Wednesday, February 26

Coming up…

Wednesday, February 12 is a holiday (no class)
Monday, February 17 is a holiday (no class)
Tuesday, February 18 follows a Monday schedule (so next week, we have class Tuesday and Wednesday)

Homework guidelines and tips

February 5, 2025 / Kate Poirier / 0 Comments

Here are some tips for writing homework, especially for questions involving proofs.

Draw at least one diagram for every proof/solution/calculation.
For any step of a proof or calculation, make sure you include a reason that your claim is true.
Homework hints are not optional; make sure you follow them closely.
You should have at least one rough copy—but possibly several rough copies—of your solutions for each problem.
Give yourself lots of space on the page; there is no need to cram your work into a small corner.
On your good copy, answer all questions in order and clearly label each

Homework #1

February 5, 2025 / Kate Poirier / 1 Comment

Hard copy due in class Wednesday, February 19

See homework guidelines and tips here

Venema page 4 #0.3.1
Venema page 4 #0.3.2
- Hint: draw these triangles carefully; your drawings do not have to be perfectly to scale, but label the sides by their lengths and the angles by their measures.
Venema page 4 #0.3.3
- Hint: When you are proving an “X if and only if Y” statement like this, you actually need to prove two separate statements: “if X, then Y,” and “if Y, then X.” (This will show that X and Y are equivalent.)
Venema page 7 #0.6.1
Venema

Lessons

Homework

Other

Lesson

Homework

Other

Lesson (Wednesday, April 2)

Homework

Other

Lessons

Homework

Other

Monday, March 17

Wednesday, March 19

Lessons

Homework

Other

Schedule

Lessons

Homework

Other

Lessons (may be adjusted)

Homework

Schedule

Schedule

Lessons

Homework and deadlines

Introduction

Summary

Lesson

Homework

Coming up…

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Course: MAT 3050 Geometry

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