TV Triangle: Solving the 55-Inch Diagonal
1. Read the essential question. 2. Write the TV width and height in your notebook. 3. Draw a right triangle and label 48, 27, and c. 4. Use a^2 + b^2 = c^2. 5. Substitute 48^2 and 27^2. 6. Show each step until you find c. 7. Compare your answer to 55 inches. 8. Explain how screen size marketing uses diagonal length. 9. Write one short claim with your math proof. 10. Turn in your work with all steps shown.
What you do
| # | What you do | Time |
|---|---|---|
| 1 | Read: “How do electronics manufacturers use right-triangle geometry to market and sell everyday screens?” | 3 min |
| 2 | Record the TV width as 48 inches and height as 27 inches. | 3 min |
| 3 | Draw a right triangle labeled 48, 27, and c in your notebook. | 5 min |
| 4 | Set up 48² + 27² = c² using a² + b² = c². | 5 min |
| 5 | Solve for c, showing every calculation through c ≈ 55.07 inches. | 15 min |
| 6 | Explain how your answer compares with 55 inches and why marketers use diagonal length. | 6 min |
| 7 | Write one short claim supported by your math proof. | 4 min |
| 8 | Turn in your notebook work with every step shown. | 4 min |
| Total | 45 mins |
Standards
- [Colorado] HS.G-SRT.C.8 - Use trigonometric ratios and the Pythagorean Theorem to solve right triangles in applied problems.
Competencies
- Entrepreneurial Skills - Critical Thinking/Problem Solving (ENT.1)
- Entrepreneurial Skills - Inquiry/Analysis (ENT.3)
Student Instructions
Read the essential question: “How do electronics manufacturers use right-triangle geometry to market screens?”
Right-triangle geometry means geometry with one 90-degree angle.
Record 48 and 27 in your notebook.
Draw a right triangle labeled 48, 27, and c.
Use a² + b² = c².
Substitute 48² + 27² for c².
Show 2304 + 729 = 3033.
Then calculate c = √3033 ≈ 55.07 inches.
Compare with 55 inches.
Diagonal means the line from one corner to the opposite corner.
Explain diagonal screen marketing.
Submit one math-supported claim and every step.
Success Criteria
- I can label a right triangle with sides 48, 27, and c.
- I can substitute 48 and 27 into the Pythagorean Theorem.
- I can show each calculation and find a diagonal of about 55.1 inches.
- I can compare my result with the marketed 55-inch screen size.
- I can support a claim about screen marketing with my math proof.