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Square root of 89

√89 ≈ 9.434. The square root of 89 is about 9.434. 89 is not a perfect square, so √89 is irrational: its decimals never end or repeat.

√89 at a glance.
Value9.43398113
Rounded9.4 (1 dp) · 9.43 (2 dp) · 9.434 (3 dp)
Simplest radical form√89
Perfect square?No — between 9² = 81 and 10² = 100
89 squared7,921

Estimating √89 in your head

Start from the nearest perfect square, 9² = 81. 89 is 8 more than that. Divide the difference by twice the root, 18, and add it:

√89 ≈ 9 + 8 ÷ 18 ≈ 9.444

The true value is 9.434, so the one-step estimate is off by about 0.01. The estimate always comes out slightly high, and it is closest when 89 is near a perfect square. The method is explained in estimating square roots in your head.

Can √89 be simplified?

No. 89 has no perfect-square factor besides 1, so √89 is already in simplest radical form.

Frequently asked questions

What is the square root of 89?

The square root of 89 is about 9.434. 89 is not a perfect square, so √89 is irrational: its decimals never end or repeat.

Is 89 a perfect square?

No. It lies between 9² = 81 and 10² = 100.

What is √89 in simplest radical form?

√89 is already in simplest form: 89 has no square factor other than 1.

Practise estimating square roots

Nearby: √88 · √90 · all square roots to 150