√ Square Root of 155 = 12.45
The square root of 155 is a value that when multiplied by itself gives 155. Learn 5 different methods to calculate √155 with step-by-step explanations.
What Is √155 and Why It Matters
The square root of 155 is 12.45 because 12.45 × 12.45 ≈ 155. 155 is not a perfect square, so its square root is an irrational number that continues forever without repeating. The simplified radical form is √155.
Understanding √155 helps build a strong foundation in algebra, geometry, and advanced mathematics. Whether you're a student learning square roots, a teacher preparing lessons, or a professional needing quick math references, this guide covers everything you need to know.
5 Ways to Calculate √155
Choose the method that works best for you, from simple mental math to advanced approximation techniques.
Mental Math (Multiplication)
Find the closest perfect squares: 12² = 144 and 13² = 169. Since 155 is between these, estimate around 12.45.
Prime Factorization
Prime factors: 155 = 5 × 31. Simplify: √155 = √155.
Long Division
Pair digits from right: 155 → 155. Continue with decimal pairs. Answer: 12.449900
Newton-Raphson (Iterative)
Formula: x₁ = (x₀ + n/x₀)/2. Starting with 12: iterations converge to 12.45.
Scientific Calculator
Press √, then 155, then = or Enter. Result: 12.449900.
Method Comparison
| Method | Best For | Result | Difficulty |
|---|---|---|---|
| Mental Math | Quick estimates | 12.45 | Easy |
| Prime Factorization | Simplifying radicals | √155 | Medium |
| Long Division | Exact decimals | 12.449900 | Hard |
| Newton-Raphson | Programming | 12.45 | Hard |
| Calculator | Everyday use | 12.449900 | Easy |
Real-World Uses of √155
Geometry & Area
A square with area 155 cm² has side length 12.45 cm. This is a classic example used in math classes worldwide.
Construction & Architecture
Builders and architects use √155 to calculate diagonal measurements, ensure right angles, and determine material quantities.
Statistics & Data Science
Standard deviation, variance, and other statistical measures frequently use square root calculations for data analysis.
Physics & Engineering
Square roots are essential in calculating velocity, acceleration, electrical resistance, and many scientific formulas.
Continue Your Learning Journey
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Frequently Asked Questions
Practice Problems
Final Thoughts
The square root of 155 is 12.45. Since 12.45 × 12.45 ≈ 155, this is an irrational number with infinite decimal places.
We've explored 5 different methods to calculate √155, from simple mental math to advanced iterative techniques. Each method offers a unique approach to understanding this fundamental mathematical concept.
"Mastering square roots opens the door to advanced mathematics and real-world problem solving."