The image you've uploaded explains the
Triangle Inequality Theorem, which is a fundamental concept in geometry. Let's break down the problem and solution step by step.
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🔷 What is the Triangle Inequality Theorem?
The
Triangle Inequality Theorem states:
> *The sum of the lengths of any two sides of a triangle must be greater than the length of the third side.*
This must be true for
all three combinations of sides in a triangle.
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🔷 Given Triangle Sides: 5, 12, and 15
We are given a triangle with side lengths:
- Side A = 5
- Side B = 12
- Side C = 15
We need to check whether these side lengths can form a valid triangle using the
Triangle Inequality Theorem.
We check all three possible sums:
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✔ Check 1: 5 + 12 > 15
→ 17 > 15 →
True
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✔ Check 2: 5 + 15 > 12
→ 20 > 12 →
True
####
✔ Check 3: 12 + 15 > 5
→ 27 > 5 →
True
Since
all three conditions are satisfied, the triangle with side lengths 5, 12, and 15
can exist.
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🔷 Explanation of the Diagram
The image shows three versions of the same triangle (with sides 5, 12, 15) and checks each pair of sides:
1.
5 + 12 > 15 → 17 > 15
✔
2.
5 + 15 > 12 → 20 > 12
✔
3.
12 + 15 > 5 → 27 > 5
✔
All are true, so this confirms that a triangle with these side lengths is possible.
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🔷 Conclusion
✔ Yes, a triangle with side lengths
5, 12, and 15 satisfies the
Triangle Inequality Theorem, so it
is a valid triangle.
This theorem helps us determine whether three given lengths can form a triangle. If even one of the inequalities fails, a triangle cannot be formed.
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📌 Summary
| Sum of Two Sides | Compare to Third Side | Result |
|------------------|------------------------|--------|
| 5 + 12 = 17 | > 15 |
✔ True |
| 5 + 15 = 20 | > 12 |
✔ True |
| 12 + 15 = 27 | > 5 |
✔ True |
✔ Valid Triangle
Let me know if you'd like to explore what happens if one inequality fails!
Parent Tip: Review the logic above to help your child master the concept of triangle inequality theorem worksheet.