Square root of 78

√78 ≈ 8.8318

√78 is an irrational number, so its decimals never end or repeat. It sits between 8 and 9 because 8² = 64 and 9² = 81.

√78 rounded

Simplest radical form

78 has no perfect-square factor other than 1, so √78 is already in simplest radical form.

Check the answer

8.8318 × 8.8318 ≈ 78.0007, which is very close to 78.

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Square roots near 78

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