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Square root of 117

√117 ≈ 10.8167. The square root of 117 is about 10.8167, which simplifies to 3√13. 117 is not a perfect square, so √117 is irrational: its decimals never end or repeat.

√117 at a glance.
Value10.81665383
Rounded10.8 (1 dp) · 10.82 (2 dp) · 10.817 (3 dp)
Simplest radical form3√13
Perfect square?No — between 10² = 100 and 11² = 121
117 squared13,689

Estimating √117 in your head

Start from the nearest perfect square, 11² = 121. 117 is 4 less than that. Divide the difference by twice the root, 22, and subtract it:

√117 ≈ 11 − 4 ÷ 22 ≈ 10.818

The true value is 10.8167, so the one-step estimate is off by about 0.002. The estimate always comes out slightly high, and it is closest when 117 is near a perfect square. The method is explained in estimating square roots in your head.

Simplifying √117

Find the largest perfect square that divides 117: it is 9, since 117 = 9 × 13. Take its root outside: √117 = √9 × √13 = 3√13.

Frequently asked questions

What is the square root of 117?

The square root of 117 is about 10.8167, which simplifies to 3√13. 117 is not a perfect square, so √117 is irrational: its decimals never end or repeat.

Is 117 a perfect square?

No. It lies between 10² = 100 and 11² = 121.

What is √117 in simplest radical form?

√117 = √(9 × 13) = 3√13.

Practise estimating square roots

Nearby: √116 · √118 · all square roots to 150