Instructions
- Think about Billy’s recent gameplay in Portal 2. Choose one or more test chambers, puzzles, or areas that he remembers clearly.
- Use the geometry vocabulary in this worksheet to describe what he saw, how objects were arranged, and how he solved problems.
- Show calculations when asked. If exact measurements are not available, use reasonable estimates and label them as estimates.
- For reflection questions, more than one answer may be correct. Explain your thinking clearly.
Helpful idea: In a portal puzzle, walls, floors, ceilings, cubes, buttons, lasers, platforms, doors, and movement paths can all be described using geometry.
Part 1: Geometry Spotting Mission
Match each geometry term with the best description. Write the correct letter on the line.
| Term | Answer | Description |
|---|---|---|
| 1. Point | _____ | A. Two lines or surfaces that meet at a right angle |
| 2. Line segment | _____ | B. A flat shape with straight sides |
| 3. Ray | _____ | C. An exact location with no size |
| 4. Parallel lines | _____ | D. Part of a line with two endpoints |
| 5. Perpendicular lines | _____ | E. Lines that stay the same distance apart and never meet |
| 6. Polygon | _____ | F. Part of a line with one endpoint that continues forever in one direction |
Example: A square floor tile is a polygon because it is a closed, flat shape with straight sides.
Now find examples from Billy’s gameplay.
| Geometry idea | Example from a Portal 2 area | Why it fits |
|---|---|---|
| Example: Rectangle | A test-chamber floor panel | It has four sides and four right angles. |
| Point | ||
| Line segment | ||
| Ray or path | ||
| Parallel lines or edges | ||
| Perpendicular lines or edges | ||
| Polygon |
Part 2: Shape Detective
Choose one object or surface from the game, such as a cube, button, platform, door, wall panel, or floor tile.
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What object did you choose?
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What two-dimensional shape does it most closely resemble when viewed from the front?
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How many sides and vertices does that shape have?
Sides: ____ Vertices: ____
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Does the object appear regular or irregular? Explain.
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Sketch the front view of the object below. Label at least two sides, one angle, and one vertex.
Part 3: Angles in Action
Identify the type of angle in each situation. Choose from acute, right, obtuse, or straight.
- A corner where a wall meets the floor at 90°: ____
- A laser beam changes direction by 45°: ____
- A platform and a wall form an angle greater than 90° but less than 180°: ____
- A character moves along a path that makes a 180° turn: ____
- A door opens to form a small angle with the wall: ____
Gameplay reflection:
Describe one moment when recognizing an angle, direction, or corner might have helped Billy solve a puzzle.
Part 4: Area and Perimeter of a Test-Chamber Panel
Suppose a square panel on a wall is 4 meters long on each side.
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Find the perimeter.
Formula: perimeter = 4 × side length
Calculation: __
Answer: ____ meters
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Find the area.
Formula: area = side length × side length
Calculation: __
Answer: ____ square meters
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If a rectangular platform is 6 meters long and 3 meters wide, find its perimeter and area.
Perimeter calculation: _____
Perimeter: ____ meters
Area calculation: __
Area: ____ square meters
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Explain why area would be useful when planning where a portal could fit on a wall or platform.
Part 5: Volume and 3-D Objects
A storage cube in a test chamber has edges that are 1 meter long.
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What is the shape of the object?
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How many faces, edges, and vertices does it have?
Faces: ____ Edges: ____ Vertices: ____
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Find its volume.
Formula: volume = length × width × height
Calculation: __
Answer: ____ cubic meter(s)
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A larger crate is 2 meters long, 2 meters wide, and 3 meters high. Find its volume.
Calculation: __
Answer: ____ cubic meters
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Why might volume matter when deciding whether an object can pass through a space?
Part 6: Movement on a Coordinate Grid
Imagine a top-down map of a test chamber. Let the starting position be point A at (1, 2). A button is at point B at (6, 2).
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How many units must Billy move horizontally from A to B?
____ units
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Are A and B on a horizontal or vertical line?
____ line
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A cube is at point C (6, 5). How many units is C above B?
____ units
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What is the total distance if Billy moves from A to B and then from B to C?
____ units
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Plot and label A, B, and C on a coordinate grid. Draw the movement path with arrows.
Part 7: Transformations and Portals
A transformation changes the position, direction, or size of a shape.
Match each transformation with the gameplay-style example.
| Transformation | Answer | Example |
|---|---|---|
| 1. Translation | _____ | A. A shape is flipped across a line |
| 2. Rotation | _____ | B. A shape slides without turning or changing size |
| 3. Reflection | _____ | C. A shape turns around a fixed point |
| 4. Dilation | _____ | D. A shape becomes larger or smaller while keeping the same form |
Answer the questions.
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When Billy walks sideways across a chamber without turning, which transformation is most similar to his movement?
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When a platform turns around a central point, which transformation is most similar?
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If a square is enlarged but keeps all four right angles, is it still similar to the original square? Explain.
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Describe one portal-related movement or object change that reminds you of a transformation.
Part 8: Design a Geometry-Based Test Chamber
Design a small test chamber on paper. Your chamber must include:
- At least one rectangle and one square
- Two parallel edges
- Two perpendicular edges
- One acute, obtuse, or straight angle
- A path with at least three line segments
- A cube, button, or other object
- A labeled start point and finish point
- At least one measurement for length, perimeter, area, or distance
Use the space below or draw on a separate sheet.
Chamber plan:
Explain how the player solves your chamber:
Geometry vocabulary used:
Part 9: Reflection and Real-World Connections
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Which geometry idea appeared most often in Billy’s gameplay?
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Which idea was easiest to recognize? Why?
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Which idea was hardest to recognize? Why?
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Where might people use area, perimeter, angles, or volume outside a video game?
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If you could add one new geometry puzzle to the game, what would it require the player to calculate or notice?
Optional Challenge
A rectangular test chamber is 12 meters long and 8 meters wide. A square platform with a side length of 3 meters takes up part of the floor.
- What is the area of the entire chamber?
- What is the area of the platform?
- How much floor area remains uncovered?
- What percentage of the chamber floor is covered by the platform? Round to the nearest whole percent.
Work:
Answer Key
Part 1
- C
- D
- F
- E
- A
- B
Student examples will vary. Accept reasonable examples connected to walls, floors, platforms, portals, buttons, doors, paths, or other game elements. A complete response should explain why each example matches the geometry term.
Part 2
Answers will vary. A rectangular door has 4 sides and 4 vertices. A square platform has 4 sides and 4 vertices. A regular shape has equal sides and equal angles; an irregular shape does not have all sides or angles equal.
Part 3
- Right
- Acute
- Obtuse
- Straight
- Acute
The gameplay reflection should connect angles, corners, directions, or alignment to solving a puzzle.
Part 4
- Perimeter = 4 × 4 = 16 meters
- Area = 4 × 4 = 16 square meters
- Perimeter = 2 × (6 + 3) = 18 meters Area = 6 × 3 = 18 square meters
- Area helps determine how much surface is available for a portal, platform, object, or safe landing space.
Part 5
- Cube
- 6 faces, 12 edges, 8 vertices
- Volume = 1 × 1 × 1 = 1 cubic meter
- Volume = 2 × 2 × 3 = 12 cubic meters
- Volume helps compare the size of an object with the amount of space available for it to move through or occupy.
Part 6
- From x = 1 to x = 6: 5 units
- Horizontal line
- From y = 2 to y = 5: 3 units
- 5 + 3 = 8 units
- The path should connect A (1, 2) to B (6, 2), then B (6, 2) to C (6, 5), with arrows showing direction.
Part 7
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B
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C
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A
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D
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Translation
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Rotation
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Yes. The two squares are similar because their corresponding angles are equal and their corresponding sides have the same ratio.
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Answers will vary. Accept examples involving moving, turning, flipping, enlarging, or shrinking an object or path.
Part 8
Check that the design includes all seven required features. The chamber explanation should describe a logical sequence for solving the puzzle and use accurate geometry vocabulary.
Part 9
Answers will vary. Strong answers should name a geometry concept, give evidence from gameplay, and connect geometry to a real-world use such as construction, architecture, engineering, design, navigation, or packing objects.
Optional Challenge
- Entire chamber area = 12 × 8 = 96 square meters
- Platform area = 3 × 3 = 9 square meters
- Uncovered area = 96 − 9 = 87 square meters
- Percentage covered = 9 ÷ 96 × 100 = 9.375%, which rounds to 9%