Square Root of 81

Calculate √81 instantly — exact value, step-by-step explanation, and properties.

√81 =
9
✓ Perfect Square

How to Calculate √81

The square root of 81 is exactly 9. This is because 9 × 9 = 81. Since 81 is a perfect square, its square root is a whole number. You can verify: 9² = 9 × 9 = 81.

√81 = 9 (because 9 × 9 = 81)

Properties of √81

Perfect Square?

Yes

81 = 9², so its square root is a whole number.

Decimal Value

9

Exact integer result.

Square Root Symbol

√81

Also written as 81^(1/2) or 81^0.5 in programming.

Related Square Root Values

Reference table of square roots near 81 for quick comparison.

Number Square Root Perfect Square? Simplified
√80 8.944271 No 4√5
√75 8.660254 No 5√3
√72 8.485281 No 6√2
√90 9.486832 No 3√10
√64 8 Yes 8
√100 10 Yes 10
√50 7.071067 No 5√2
√49 7 Yes 7
√48 6.928203 No 4√3
√45 6.708203 No 3√5

Frequently Asked Questions

What is the square root of 81?

The square root of 81 is exactly 9. Since 81 is a perfect square, √81 = 9.

Is 81 a perfect square?

Yes, 81 is a perfect square. It equals 9², meaning 9 × 9 = 81.

How do you calculate √81 by hand?

Since 81 is a perfect square, you can find √81 by identifying which integer multiplied by itself equals 81. The answer is 9, because 9 × 9 = 81.

What is √81 in simplified radical form?

√81 = 9. Since it's a perfect square, no radical form is needed.

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