√379 at a glance
- Exact value
- √379
- Decimal (10 places)
- 19.4679223339
- Rounded
- 19.5 · 19.47 · 19.468
- Perfect square?
- No — between 19² and 20²
- Rational?
- Irrational
- Both square roots
- ±19.467922
- Prime factorization
- 379
- Cube root
- 7.236797
How to simplify √379
379 is a prime number, so its only factors are 1 and 379. There is no perfect-square factor to pull out, which means √379 is already in its simplest radical form.
The square root of any prime is irrational. If √379 were a fraction a/b in lowest terms, then a² = 379b², so 379 would divide a — and then 379 would divide b too, contradicting “lowest terms.” That is why the decimal 19.4679223339 is only a rounded value.
Where √379 sits between perfect squares
361 = 19² and 400 = 20² are the nearest perfect squares, so √379 lies between 19 and 20. 379 is 18 above 361 and 21 below 400, so the root is closer to 19.
- Straight line between 361 and 400: 19.4615 (0.03% low)
- Tangent from 19, i.e. 19 + 18 ÷ 38: 19.4737 (0.03% high)
- Tangent from 20, i.e. 20 − 21 ÷ 40: 19.4750 (0.04% high)
For √379 the tangent at 19 wins, missing by only 0.0058. Tangent estimates shine when the number sits close to a perfect square — here 379 is just 18 above 361.
Finding √379 with the Babylonian method
If a guess is too big, 379 ÷ 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√379) in one step.
Start from the nearest whole number, 19 (19² = 361):
| Step | Guess x | 379 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 19.0000000000 | 19.9473684211 | 19.4736842105 | 2 |
| 2 | 19.4736842105 | 19.4621621622 | 19.4679231863 | 6 |
| 3 | 19.4679231863 | 19.4679214815 | 19.4679223339 | 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 √379 = 19.4679223339 to every decimal shown.
√379 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √379 the pattern is [19; 2, 7, 3, 2, 2, 6, 12, 1, 4, 1, 1, 1, …] with the block of 30 terms after the semicolon repeating forever (only the first 12 of the 30 are shown). A pattern that never ends is one more proof that √379 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 |
|---|---|---|
| 19/1 | 19.0000000000 | 4.7 × 10⁻¹ |
| 39/2 | 19.5000000000 | 3.2 × 10⁻² |
| 292/15 | 19.4666666667 | 1.3 × 10⁻³ |
| 915/47 | 19.4680851064 | 1.6 × 10⁻⁴ |
| 2,122/109 | 19.4678899083 | 3.2 × 10⁻⁵ |
| 5,159/265 | 19.4679245283 | 2.2 × 10⁻⁶ |
The same fractions solve Pell’s equation, x² − 379y² = 1. Its smallest solution in positive whole numbers is x = 12,941,197,220,540,690, y = 664,744,650,125,541 — 17 digits for x, even though 379 is small, which is what makes Pell’s equation famous.
√379 in geometry and everyday measurements
- A square patio or deck of 379 square feet is about 19.47 ft (19 ft 6 in) on each side, so edging all the way around takes 4 × √379 ≈ 77.9 ft.
- 379 is not a sum of two whole-number squares — 379 is itself a prime that is one less than a multiple of 4, which rules that out — so √379 is never the diagonal of a rectangle with whole-number sides. It is, however, the space diagonal of a 3 × 3 × 19 box, because 3² + 3² + 19² = 379.
Square roots near √379 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √376 | 2√94 | 19.3907 | No |
| √377 | √377 | 19.4165 | No |
| √378 | 3√42 | 19.4422 | No |
| √379 | √379 | 19.4679 | No |
| √380 | 2√95 | 19.4936 | No |
| √381 | √381 | 19.5192 | No |
| √382 | √382 | 19.5448 | No |
- The cube root of 379 is about 7.236797.
- Squaring undoes the root: (√379)² = 379, while 379² = 143,641 — the number whose square root is 379.
Frequently asked questions
What is the square root of 379?
The square root of 379 is √379, about 19.4679223339. The negative root, −19.467922, also squares to 379.
Is the square root of 379 rational or irrational?
Irrational. 379 is not a perfect square — it falls between 361 and 400 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √379 be simplified?
No. 379 is prime, so there is no perfect square to take out of the radical.
What is √379 rounded to two decimal places?
√379 ≈ 19.47 to two decimal places (19.5 to one, 19.468 to three). Check: 19.47² = 379.0809, close to 379.