BrightChamps Logo
Login
Creative Math Ideas Image
Live Math Learners Count Icon139 Learners

Last updated on May 26th, 2025

Math Whiteboard Illustration

Square Root of 17.8

Professor Greenline Explaining Math Concepts

If a number is multiplied by itself, the result is a square. The inverse of squaring a number is finding its square root. Square roots have applications in various fields, such as engineering, finance, and more. Here, we will discuss the square root of 17.8.

Square Root of 17.8 for Global Students
Professor Greenline from BrightChamps

What is the Square Root of 17.8?

The square root is the inverse operation of squaring a number. 17.8 is not a perfect square. The square root of 17.8 can be expressed in both radical and exponential forms. In radical form, it is expressed as √17.8, whereas in exponential form it is (17.8)^(1/2). The square root of 17.8 is approximately 4.21637, which is an irrational number because it cannot be expressed as a simple fraction p/q, where p and q are integers and q ≠ 0.square root of 17.8

Professor Greenline from BrightChamps

Finding the Square Root of 17.8

The prime factorization method is suitable for perfect squares. However, for non-perfect squares like 17.8, methods such as the long-division method and approximation method are used. Let us now learn the following methods:

 

  • Prime factorization method
  • Long division method
  • Approximation method
Professor Greenline from BrightChamps

Square Root of 17.8 by Prime Factorization Method

Prime factorization involves expressing a number as a product of prime numbers. Since 17.8 is not an integer, prime factorization is not applicable directly. Therefore, calculating the square root of 17.8 using prime factorization is not possible.

Professor Greenline from BrightChamps

Square Root of 17.8 by Long Division Method

The long division method is useful for non-perfect square numbers. This method allows us to find the square root more accurately. Here's how to find the square root using the long division method, step by step:

 

Step 1: Begin by grouping the digits of the number from right to left. For 17.8, we consider it as 1780 (after multiplying by 100 to remove the decimal).

 

Step 2: Find a number whose square is less than or equal to 17. The number is 4 because 4^2 = 16.

 

Step 3: Subtract 16 from 17, leaving a remainder of 1. Bring down the next pair, 80, to make it 180.

 

Step 4: Double the quotient (4), which gives us 8, and use it as the first digit of our new divisor. Find a number n such that 8n × n is less than or equal to 180.

 

Step 5: The number n is 2 because 82 × 2 = 164, and subtracting 164 from 180 gives a remainder of 16.

 

Step 6: Add a decimal point to the quotient and bring down 00, making it 1600.

 

Step 7: The next divisor is 84n, find n such that 84n × n is less than or equal to 1600.

 

Step 8: Continue this process until you achieve the desired precision.

 

The square root of 17.8 is approximately 4.21637.

Professor Greenline from BrightChamps

Square Root of 17.8 by Approximation Method

The approximation method is a straightforward way to estimate the square root of a given number.

 

Step 1: Identify two perfect squares between which 17.8 falls.

The closest perfect squares are 16 and 25.

Thus, √17.8 is between 4 and 5.

 

Step 2: Apply the approximation formula:

(Given number - smaller perfect square) / (Larger perfect square - smaller perfect square).

Using this formula: (17.8 - 16) / (25 - 16) = 1.8 / 9 = 0.2

 

Step 3: Add the smaller square root (4) to the decimal value obtained: 4 + 0.2 = 4.2.

So, the approximate square root of 17.8 is 4.2.

Max Pointing Out Common Math Mistakes

Common Mistakes and How to Avoid Them in the Square Root of 17.8

Students often make errors when finding square roots, such as neglecting the negative root or skipping steps in the long division method. Here are some common mistakes to watch for:

Mistake 1

Red Cross Icon Indicating Mistakes to Avoid in This Math Topic

Forgetting about the negative square root

Green Checkmark Icon Indicating Correct Solutions in This Math Topic

Students should be aware that numbers have both positive and negative square roots. While the positive square root is often used, it is crucial to remember that a negative square root exists.

 

For example, √17.8 = 4.21637, but there is also -4.21637.

Max from BrightChamps Saying "Hey"

Square Root of 17.8 Examples

Ray, the Character from BrightChamps Explaining Math Concepts
Max, the Girl Character from BrightChamps

Problem 1

Can you help Max find the area of a square box if its side length is given as √17.8?

Ray, the Boy Character from BrightChamps Saying "Let’s Begin"

The area of the square is approximately 17.8 square units.

Explanation

The area of a square is side^2.

Given that the side length is √17.8, the area is (√17.8)^2 = 17.8.

Therefore, the area of the square box is 17.8 square units.

Max from BrightChamps Praising Clear Math Explanations
Max, the Girl Character from BrightChamps

Problem 2

A square-shaped building measuring 17.8 square feet is built; if each of the sides is √17.8, what will be the square feet of half of the building?

Ray, the Boy Character from BrightChamps Saying "Let’s Begin"

8.9 square feet

Explanation

Since the building is square-shaped, half of its area is simply half of 17.8.

Dividing 17.8 by 2 gives 8.9 square feet.

Max from BrightChamps Praising Clear Math Explanations
Max, the Girl Character from BrightChamps

Problem 3

Calculate √17.8 × 5.

Ray, the Boy Character from BrightChamps Saying "Let’s Begin"

Approximately 21.08185

Explanation

First, find the square root of 17.8, which is approximately 4.21637.

Then, multiply 4.21637 by 5, resulting in approximately 21.08185.

Max from BrightChamps Praising Clear Math Explanations
Max, the Girl Character from BrightChamps

Problem 4

What will be the square root of (9 + 8.8)?

Ray, the Boy Character from BrightChamps Saying "Let’s Begin"

The square root is approximately ±4.21637

Explanation

First, sum the numbers: 9 + 8.8 = 17.8.

Then find the square root of 17.8, which is approximately ±4.21637.

Max from BrightChamps Praising Clear Math Explanations
Max, the Girl Character from BrightChamps

Problem 5

Find the perimeter of the rectangle if its length ‘l’ is √17.8 units and the width ‘w’ is 5 units.

Ray, the Boy Character from BrightChamps Saying "Let’s Begin"

Approximately 18.43274 units

Explanation

Perimeter of the rectangle = 2 × (length + width).

Substituting the values, we get 2 × (√17.8 + 5) = 2 × (4.21637 + 5) = 2 × 9.21637 ≈ 18.43274 units.

Max from BrightChamps Praising Clear Math Explanations
Ray Thinking Deeply About Math Problems

FAQ on Square Root of 17.8

1.What is √17.8 in its simplest form?

Math FAQ Answers Dropdown Arrow

2.Is 17.8 a perfect square?

Math FAQ Answers Dropdown Arrow

3.Calculate the square of 17.8.

Math FAQ Answers Dropdown Arrow

4.Is 17.8 a prime number?

Math FAQ Answers Dropdown Arrow

5.What are the factors of 17.8?

Math FAQ Answers Dropdown Arrow
Professor Greenline from BrightChamps

Important Glossaries for the Square Root of 17.8

  • Square root: A square root of a number is a value that, when multiplied by itself, gives the original number. For example, √16 = 4.
     
  • Irrational number: An irrational number cannot be represented as a simple fraction. It has non-repeating, non-terminating decimal expansions. Example: √17.8 is irrational.
     
  • Decimal: A decimal is a number that has a whole number part and a fractional part separated by a decimal point, such as 4.21637.
     
  • Long division method: A method used to find square roots of non-perfect squares by systematically dividing and averaging.
     
  • Perfect square: A perfect square is a number that is the square of an integer, like 16, which is 4^2.
Math Teacher Background Image
Math Teacher Image

Jaskaran Singh Saluja

About the Author

Jaskaran Singh Saluja is a math wizard with nearly three years of experience as a math teacher. His expertise is in algebra, so he can make algebra classes interesting by turning tricky equations into simple puzzles.

Math Teacher Fun Facts Image
Max, the Girl Character from BrightChamps

Fun Fact

: He loves to play the quiz with kids through algebra to make kids love it.

INDONESIA - Axa Tower 45th floor, JL prof. Dr Satrio Kav. 18, Kel. Karet Kuningan, Kec. Setiabudi, Kota Adm. Jakarta Selatan, Prov. DKI Jakarta
INDIA - H.No. 8-2-699/1, SyNo. 346, Rd No. 12, Banjara Hills, Hyderabad, Telangana - 500034
SINGAPORE - 60 Paya Lebar Road #05-16, Paya Lebar Square, Singapore (409051)
USA - 251, Little Falls Drive, Wilmington, Delaware 19808
VIETNAM (Office 1) - Hung Vuong Building, 670 Ba Thang Hai, ward 14, district 10, Ho Chi Minh City
VIETNAM (Office 2) - 143 Nguyễn Thị Thập, Khu đô thị Him Lam, Quận 7, Thành phố Hồ Chí Minh 700000, Vietnam
Dubai - BrightChamps, 8W building 5th Floor, DAFZ, Dubai, United Arab Emirates
UK - Ground floor, Redwood House, Brotherswood Court, Almondsbury Business Park, Bristol, BS32 4QW, United Kingdom