What is the square root of 21?

The square root of 21 is a number that, when multiplied by itself, equals 21. It is an irrational number, meaning it cannot be expressed as a simple fraction. The approximate value of the square root of 21 is about 4.58.

Understanding Square Roots

To grasp the concept of square roots, consider the following:

• The square root of a number x is a value y such that y × y = x.
• For example, the square root of 16 is 4 because 4 × 4 = 16.

Calculating Square Roots

For numbers that are not perfect squares, like 21, you can use a calculator or estimation methods to find the square root. Here’s a quick way to estimate:

• Identify the nearest perfect squares: 16 (4²) and 25 (5²).
• Since 21 is between these two, its square root will be between 4 and 5.

Thus, the square root of 21 is approximately 4.58, which you can round to two decimal places for simplicity.