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Square Root of 20 + Solution With Free Steps

20 has a square root of 4.47. √20 = 4.47  is the way to express the square root of that number. Multiplying the result by itself gives us 20. The result of 20 times 20 is 20, which is the same as 4.47 times 4.47. 20 is a rational number.

In this article, we will analyze and find the square root of 20 using various mathematical techniques, such as the approximation method and the long division method.

What Is the Square Root Of 20?

The square root of the number 20 is 4.47.

The square root can be defined as the quantity that can be doubled to produce the square of that similar quantity. In simple words, it can be explained as:

√20 = √(4.47 x 4.47)

√20 = √(4.47)$^2$

√20 = ±4.47

The square can be canceled with the square root as it is equivalent to 1/2; therefore, obtaining 4.47. Hence 4.47 is 20’s square root. The square root generates both positive and negative integers.

How To Calculate the Square Root of 20?

You can calculate the square root of 20 using any of two vastly used techniques in mathematics; one is the Approximation technique, and the other is the Long Division method.

The symbol √ is interpreted as 20 raised to the power 1/2. So any number, when multiplied by itself, produces its square, and when the square root of any squared number is taken, it produces the actual number.

Let us discuss each of them to understand the concepts better.

Square Root by Long Division Method

The process of long division is one of the most common methods used to find the square roots of a given number. It is easy to comprehend and provides more reliable and accurate answers. The long division method reduces a multi-digit number to its equal parts.

Learning how to find the square root of a number is easy with the long division method. All you need are five primary operations- divide, multiply, subtract, bring down or raise, then repeat.

Following are the simple steps that must be followed to find the square root of 20 using the long division method:

Step 1

First, write the given number 20 in the division symbol, as shown in figure 1.

Step 2

Starting from the right side of the number, divide the number 20 into pairs such as 20 and 00.

Step 3

Now divide the digit 20 by a number, giving a number either 4 or less than 4. Therefore, in this case, the remainder is 4, whereas the quotient is also 4.

Step 4

After this, bring down the next pair 00. Now the dividend is 400. To find the next divisor, we need to double our quotient obtained before. Doubling 4 gives 8; hence consider it as the next divisor.

Step 5

Now pair 2 with another number to make a new divisor that results in $\leq$ 400 when multiplied with the divisor. If the number is not a perfect square, add pair of zeros to the right of the number before starting division.

Step 6

Adding 4 to the divisor and multiplying 84 with 4 results in 336 < 400. The remainder obtained is 64. Move the next pair of zeros down and repeat the same process mentioned above.

Step 7

Keep on repeating the same steps till the zero remainder is obtained or if the division process continues infinitely, solve to two decimal places.

Step 8

The resulting quotient of 4.47 is the square root of 20. Figure 1 given below shows the long division process in detail:

Square root of

Figure 1

Square Root by Approximation Method

The approximation method involves guessing the square root of the non-perfect square number by dividing it by the perfect square lesser or greater than that number and taking the average.

The given detailed steps must be followed to find the square root of 20 using the approximation technique.

Step 1

Consider a perfect square number 4 less than 20.

Step 2

Now divide 20 by 4.

20 ÷ 4 = 5

Step 3

Now take the average of 4  and 5. The resulting number is approximately equivalent to the square root of 20.

(4 + 5 ) ÷ 2 = 4.5

Important points

  • The number 20 is not a perfect square.
  • The number 20 is a irrational number.
  • The number 20 can be split into its prime factorization.

Is Square Root of 20 a Perfect Square?

The number 20 is not a perfect square. A number is a perfect square if it splits into two equal parts or identical whole numbers. If a number is a perfect square, it is also rational.

A number expressed in p/q form is called a rational number. All the natural numbers are rational. A square root of a perfect square is a whole number; therefore, a perfect square is a rational number.

A number that is not a perfect square is irrational as it is a decimal number. As far as 20 is concerned, it is not a perfect square. It can be proved as below:

Factorization of 20 results in 4 x 5.

Taking the square root of the above expression gives:

= √(4 x 5)

= (4 x 5)$^{1/2}$

= 4.47

This shows that 20 is not a perfect square as it has decimal places; hence it is an irrational number.

Therefore the above discussion proves that the square root of 20 is equivalent to 4.47.

Images/mathematical drawings are created with GeoGebra.

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