√175 at a glance
- Exact value
- 5√7
- Decimal (10 places)
- 13.2287565553
- Rounded
- 13.2 · 13.23 · 13.229
- Perfect square?
- No — between 13² and 14²
- Rational?
- Irrational
- Both square roots
- ±13.228757
- Prime factorization
- 5² × 7
- Cube root
- 5.593445
How to simplify √175
Look for the largest perfect square that divides 175. Here it is 25 (5²), because 175 = 25 × 7 and 7 has no square factor left:
The prime factorization tells the same story: 175 = 5² × 7. Each pair of equal primes leaves the radical as one factor, so 5 comes out and 7 stays inside.
Check: (5√7)² = 5² × 7 = 25 × 7 = 175. As a decimal, 5√7 = 5 × 2.6457513111 ≈ 13.2287565553.
Where √175 sits between perfect squares
169 = 13² and 196 = 14² are the nearest perfect squares, so √175 lies between 13 and 14. 175 is 6 above 169 and 21 below 196, so the root is closer to 13.
- Straight line between 169 and 196: 13.2222 (0.05% low)
- Tangent from 13, i.e. 13 + 6 ÷ 26: 13.2308 (0.02% high)
- Tangent from 14, i.e. 14 − 21 ÷ 28: 13.2500 (0.16% high)
For √175 the tangent at 13 wins, missing by only 0.002. Tangent estimates shine when the number sits close to a perfect square — here 175 is just 6 above 169.
Finding √175 with the Babylonian method
If a guess is too big, 175 ÷ x is too small by about the same amount, so their average lands much closer. In fact an error of e shrinks to roughly e² ÷ (2√175) in one step.
Start from the nearest whole number, 13 (13² = 169):
| Step | Guess x | 175 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 13.0000000000 | 13.4615384615 | 13.2307692308 | 2 |
| 2 | 13.2307692308 | 13.2267441860 | 13.2287567084 | 6 |
| 3 | 13.2287567084 | 13.2287564022 | 13.2287565553 | all 10 shown |
The count of correct decimals went 2, 6 and all 10 over 3 steps — roughly doubling each time — until the guess matched √175 = 13.2287565553 to every decimal shown.
√175 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √175 the pattern is [13; 4, 2, 1, 2, 4, 26] with the block of 6 terms after the semicolon repeating forever. A pattern that never ends is one more proof that √175 is irrational.
Cutting the continued fraction off early gives the best fractions for approximating the root — no fraction with a smaller denominator comes closer:
| Fraction | Decimal | Error |
|---|---|---|
| 13/1 | 13.0000000000 | 2.3 × 10⁻¹ |
| 53/4 | 13.2500000000 | 2.1 × 10⁻² |
| 119/9 | 13.2222222222 | 6.5 × 10⁻³ |
| 172/13 | 13.2307692308 | 2.0 × 10⁻³ |
| 463/35 | 13.2285714286 | 1.9 × 10⁻⁴ |
| 2,024/153 | 13.2287581699 | 1.6 × 10⁻⁶ |
The same fractions solve Pell’s equation, x² − 175y² = 1. Its smallest solution in positive whole numbers is x = 2,024, y = 153.
√175 in geometry and everyday measurements
- A square room or garden bed covering 175 square feet measures about 13.23 ft (13 ft 3 in) along each wall.
- 175 is not a sum of two whole-number squares — the prime factor 7 (one less than a multiple of 4) appears an odd number of times, which rules that out — so √175 is never the diagonal of a rectangle with whole-number sides. It is not a sum of three positive squares either, so no whole-number box has √175 as its space diagonal.
- Since √175 = 5√7, a length of √175 is exactly 5 copies of the length √7 laid end to end.
Square roots near √175 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √172 | 2√43 | 13.1149 | No |
| √173 | √173 | 13.1529 | No |
| √174 | √174 | 13.1909 | No |
| √175 | 5√7 | 13.2288 | No |
| √176 | 4√11 | 13.2665 | No |
| √177 | √177 | 13.3041 | No |
| √178 | √178 | 13.3417 | No |
- The cube root of 175 is about 5.593445.
- Four times the radicand doubles the root: √700 = 2 × √175 ≈ 26.457513.
Frequently asked questions
What is the square root of 175?
The square root of 175 is 5√7 in simplest radical form, which is about 13.2287565553. The negative root, −13.228757, also squares to 175.
Is the square root of 175 rational or irrational?
Irrational. 175 is not a perfect square — it falls between 169 and 196 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √175 be simplified?
Yes. The largest perfect square dividing 175 is 25, so √175 = √25 × √7 = 5√7.
What is √175 rounded to two decimal places?
√175 ≈ 13.23 to two decimal places (13.2 to one, 13.229 to three). Check: 13.23² = 175.0329, close to 175.