√370 at a glance
- Exact value
- √370
- Decimal (10 places)
- 19.2353840617
- Rounded
- 19.2 · 19.24 · 19.235
- Perfect square?
- No — between 19² and 20²
- Rational?
- Irrational
- Both square roots
- ±19.235384
- Prime factorization
- 2 × 5 × 37
- Cube root
- 7.179054
How to simplify √370
The prime factorization of 370 is 2 × 5 × 37. Every prime appears only once, so there is no pair to bring outside the radical — √370 is already in simplest form (a "square-free" radicand).
A whole number has a rational square root only when every prime in its factorization appears an even number of times. In 370, 2, 5 and 37 appear an odd number of times, so √370 is irrational and 19.2353840617 is a rounded value.
Where √370 sits between perfect squares
361 = 19² and 400 = 20² are the nearest perfect squares, so √370 lies between 19 and 20. 370 is 9 above 361 and 30 below 400, so the root is closer to 19.
- Straight line between 361 and 400: 19.2308 (0.02% low)
- Tangent from 19, i.e. 19 + 9 ÷ 38: 19.2368 (0.01% high)
- Tangent from 20, i.e. 20 − 30 ÷ 40: 19.2500 (0.08% high)
For √370 the tangent at 19 wins, missing by only 0.0015. Tangent estimates shine when the number sits close to a perfect square — here 370 is just 9 above 361.
Finding √370 with the Babylonian method
The idea is ancient. A Babylonian clay tablet catalogued as YBC 7289, about 3,800 years old, records √2 correct to roughly six decimal places, and Heron of Alexandria described this averaging rule in the first century AD.
Start from the nearest whole number, 19 (19² = 361):
| Step | Guess x | 370 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 19.0000000000 | 19.4736842105 | 19.2368421053 | 2 |
| 2 | 19.2368421053 | 19.2339261286 | 19.2353841169 | 7 |
| 3 | 19.2353841169 | 19.2353840064 | 19.2353840617 | all 10 shown |
The count of correct decimals went 2, 7 and all 10 over 3 steps — roughly doubling each time — until the guess matched √370 = 19.2353840617 to every decimal shown.
√370 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √370 the pattern is [19; 4, 4, 38] with the block of 3 terms after the semicolon repeating forever. A pattern that never ends is one more proof that √370 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 | 2.4 × 10⁻¹ |
| 77/4 | 19.2500000000 | 1.5 × 10⁻² |
| 327/17 | 19.2352941176 | 9.0 × 10⁻⁵ |
| 12,503/650 | 19.2353846154 | 5.5 × 10⁻⁷ |
| 50,339/2,617 | 19.2353840275 | 3.4 × 10⁻⁸ |
| 213,859/11,118 | 19.2353840619 | 2.1 × 10⁻¹⁰ |
The same fractions solve Pell’s equation, x² − 370y² = 1. Its smallest solution in positive whole numbers is x = 213,859, y = 11,118. Because the period is odd, the equation with −1 on the right also has a solution: 327² − 370 × 17² = −1.
√370 in geometry and everyday measurements
- A square patio or deck of 370 square feet is about 19.24 ft (19 ft 3 in) on each side, so edging all the way around takes 4 × √370 ≈ 76.9 ft.
- 370 = 3² + 19² = 9² + 17², so by the Pythagorean theorem √370 is the diagonal of rectangles measuring 3 × 19 and 9 × 17 — and the distance between the points (0, 0) and (3, 19) on a grid.
Square roots near √370 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √367 | √367 | 19.1572 | No |
| √368 | 4√23 | 19.1833 | No |
| √369 | 3√41 | 19.2094 | No |
| √370 | √370 | 19.2354 | No |
| √371 | √371 | 19.2614 | No |
| √372 | 2√93 | 19.2873 | No |
| √373 | √373 | 19.3132 | No |
- The cube root of 370 is about 7.179054.
- Squaring undoes the root: (√370)² = 370, while 370² = 136,900 — the number whose square root is 370.
Frequently asked questions
What is the square root of 370?
The square root of 370 is √370, about 19.2353840617. The negative root, −19.235384, also squares to 370.
Is the square root of 370 rational or irrational?
Irrational. 370 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 √370 be simplified?
No. 370 = 2 × 5 × 37 has no repeated prime factor, so there is no perfect square to take out of the radical.
What is √370 rounded to two decimal places?
√370 ≈ 19.24 to two decimal places (19.2 to one, 19.235 to three). Check: 19.24² = 370.1776, close to 370.