√472 at a glance
- Exact value
- 2√118
- Decimal (10 places)
- 21.7255609824
- Rounded
- 21.7 · 21.73 · 21.726
- Perfect square?
- No — between 21² and 22²
- Rational?
- Irrational
- Both square roots
- ±21.725561
- Prime factorization
- 2³ × 59
- Cube root
- 7.785993
How to simplify √472
Look for the largest perfect square that divides 472. Here it is 4 (2²), because 472 = 4 × 118 and 118 has no square factor left:
The prime factorization tells the same story: 472 = 2³ × 59. Each pair of equal primes leaves the radical as one factor, so 2 comes out and 2 × 59 stays inside.
Check: (2√118)² = 2² × 118 = 4 × 118 = 472. As a decimal, 2√118 = 2 × 10.8627804912 ≈ 21.7255609824.
Where √472 sits between perfect squares
441 = 21² and 484 = 22² are the nearest perfect squares, so √472 lies between 21 and 22. 472 is 31 above 441 and 12 below 484, so the root is closer to 22.
- Straight line between 441 and 484: 21.7209 (0.02% low)
- Tangent from 21, i.e. 21 + 31 ÷ 42: 21.7381 (0.06% high)
- Tangent from 22, i.e. 22 − 12 ÷ 44: 21.7273 (0.01% high)
For √472 the tangent at 22 wins, missing by only 0.0017. Tangent estimates shine when the number sits close to a perfect square — here 472 is just 12 below 484.
Finding √472 with the Babylonian method
Picture a rectangle with an area of 472 and one side x; the other side must be 472 ÷ x. Averaging the two sides gives a rectangle that is closer to a square, and the side of that square is exactly √472.
Start from the nearest whole number, 22 (22² = 484):
| Step | Guess x | 472 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 22.0000000000 | 21.4545454545 | 21.7272727273 | 2 |
| 2 | 21.7272727273 | 21.7238493724 | 21.7255610498 | 7 |
| 3 | 21.7255610498 | 21.7255609150 | 21.7255609824 | 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 √472 = 21.7255609824 to every decimal shown.
√472 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √472 the pattern is [21; 1, 2, 1, 1, 1, 4, 5, 4, 1, 1, 1, 2, …] with the block of 14 terms after the semicolon repeating forever (only the first 12 of the 14 are shown). A pattern that never ends is one more proof that √472 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 |
|---|---|---|
| 21/1 | 21.0000000000 | 7.3 × 10⁻¹ |
| 22/1 | 22.0000000000 | 2.7 × 10⁻¹ |
| 65/3 | 21.6666666667 | 5.9 × 10⁻² |
| 87/4 | 21.7500000000 | 2.4 × 10⁻² |
| 152/7 | 21.7142857143 | 1.1 × 10⁻² |
| 239/11 | 21.7272727273 | 1.7 × 10⁻³ |
The same fractions solve Pell’s equation, x² − 472y² = 1. Its smallest solution in positive whole numbers is x = 306,917, y = 14,127.
√472 in geometry and everyday measurements
- A square garage floor of 472 square feet measures about 21.73 ft (21 ft 9 in) per side, and its corner-to-corner diagonal is √944 ≈ 30.7 ft.
- 472 is not a sum of two whole-number squares — the prime factor 59 (one less than a multiple of 4) appears an odd number of times, which rules that out — so √472 is never the diagonal of a rectangle with whole-number sides. It is, however, the space diagonal of a 2 × 12 × 18 box, because 2² + 12² + 18² = 472.
- Since √472 = 2√118, a length of √472 is exactly 2 copies of the length √118 laid end to end.
Square roots near √472 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √469 | √469 | 21.6564 | No |
| √470 | √470 | 21.6795 | No |
| √471 | √471 | 21.7025 | No |
| √472 | 2√118 | 21.7256 | No |
| √473 | √473 | 21.7486 | No |
| √474 | √474 | 21.7715 | No |
| √475 | 5√19 | 21.7945 | No |
- The cube root of 472 is about 7.785993.
- Because 472 = 4 × 118, the root is twice √118: 2 × 10.86278 ≈ 21.725561.
Frequently asked questions
What is the square root of 472?
The square root of 472 is 2√118 in simplest radical form, which is about 21.7255609824. The negative root, −21.725561, also squares to 472.
Is the square root of 472 rational or irrational?
Irrational. 472 is not a perfect square — it falls between 441 and 484 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √472 be simplified?
Yes. The largest perfect square dividing 472 is 4, so √472 = √4 × √118 = 2√118.
What is √472 rounded to two decimal places?
√472 ≈ 21.73 to two decimal places (21.7 to one, 21.726 to three). Check: 21.73² = 472.1929, close to 472.