Create a high-impact, highly interactive 10th-grade Geometry lesson deck on the "Triangle Inequality Theorem: Finding the Range of the Third Side." The lesson must be structured for a 45-minute class period, combining conceptual discovery, algebraic formulation, and real-time student interaction slides. Use a modern, clean academic theme with high contrast. Incorporate the following specific slide structure and interaction instructions: Slide 1: Title Slide - Title: The Triangle Inequality Theorem - Subtitle: Finding the Range of a Missing Side Slide 2: Interaction Slide (Predictive Live Multiple-Choice Poll) - Question: "Can segments of 4 cm, 5 cm, and 10 cm form a closed triangle?" - Options: Yes / No / Not sure - Instruction for AI: Include a brief text note at the bottom telling the teacher to reveal the answer dynamically after students vote. Slide 3: Conceptual Proof (The "Why") - Title: Why 4, 5, and 10 Fail - Content: Explain that the two shorter sides must be strictly greater than the longest side (4 + 5 = 9, which is less than 10). Visually or textually describe the segments flattening out into a straight line before they can connect at a vertex. Slide 4: Core Theorem Definition - Title: The Triangle Inequality Theorem - Core Formula: State the three compound inequalities: a + b > c, a + c > b, and b + c > a. - Definition: Any side of a triangle must be longer than the difference of the other two sides, but shorter than their sum. Slide 5: Guided Discovery: Building the Range Formula - Title: Deriving the Range Shortcut - Content: Show step-by-step how to find the bounds for a missing side 'x' given sides 'a' and 'b' (where a ≥ b). - Lower Bound: x > a - b (Difference) - Upper Bound: x < a + b (Sum) - Combined Formula: (a - b) < x < (a + b) Slide 6: Interaction Slide (Live Word Cloud or Open-Text Check) - Question: "If a triangle has side lengths of 6 and 14, what is the lower limit and upper limit for the third side x?" - Content: Direct students to write their answer as a compound inequality (e.g., 8 < x < 20). Slide 7: Step-by-Step Example (The Trick Case) - Title: Example: What if the sides are equal? - Scenario: Given two sides of 7 and 7. - Math Steps: - Difference: 7 - 7 = 0 - Sum: 7 + 7 = 14 - Range Result: 0 < x < 14. Explain why a side cannot be exactly 0 (it collapses into a line segment/degenerate triangle). Slide 8: Interaction Slide (Live Multiple-Choice Quiz) - Question: "Which of the following CANNOT be the length of the third side of a triangle with given sides 8 and 11?" - Options: A) 4, B) 11, C) 3, D) 18 - Correct Answer: C) 3 (because the range is 3 < x < 19, and 3 is not strictly greater than 3). Slide 9: Lesson Summary & Exit Ticket Setup - Bullet points recapping: Difference < x < Sum. - A final prompt for an open-ended student reflection question: "In your own words, why can't the third side equal the exact sum of the other two sides?"