Last updated on May 26th, 2025
The square root of 121 is a value “y” such that when “y” is multiplied by itself → y ⤫ y, the result is 121. The number 121 has a unique non-negative square root, called the principal square root.
The square root of 121 is ±11, where 11 is the positive solution of the equation x2 = 121. Finding the square root is just the inverse of squaring a number and hence, squaring 11 will result in 121.
The square root of 121 is written as √121 in radical form, where the ‘√’ sign is called the “radical” sign. In exponential form, it is written as (121)1/2
We can find the square root of 121 through various methods. They are:
The prime factorization of 121 can be found by dividing the number by prime numbers and continuing to divide the quotients until they can’t be separated anymore, i.e., we first prime factorize 121 and then make pairs of two to get the square root.
So, Prime factorization of 121 = 11 × 11
Square root of 121= √[11 × 11] = 11
This method is used for obtaining the square root for non-perfect squares, mainly. It usually involves the division of the dividend by the divisor, getting a quotient and a remainder too sometimes.
Follow the steps to calculate the square root of 121:
Step 1: Write the number 121 and draw a bar above the pair of digits from right to left.
Step 2: Now, find the greatest number whose square is less than or equal to 1. Here, it is
1 because 12=1 < =1
Step 3: now divide 121 by 1 (the number we got from Step 2) such that we get 1 as a quotient, and we get a remainder. Double the divisor 1, we get 2, and then the largest possible number A1=1 is chosen such that when 1 is written beside the new divisor 2, a 2-digit number is formed →21, and multiplying 1 with 21 gives 21, which
when subtracted from 21, gives 0
Repeat this process until you reach the remainder of 0.
Step 4: The quotient obtained is the square root of 121. In this case, it is 11.
We know that the sum of the first n odd numbers is n2. We will use this fact to find square roots through the repeated subtraction method. Furthermore, we just have to subtract consecutive odd numbers from the given number, starting from 1. The square root of the given number will be the count of the number of steps required to obtain 0. Here are the steps:
Step 1: take the number 121 and then subtract the first odd number from it. Here, in this case, it is 121-1=120
Step 2: we have to subtract the next odd number from the obtained number until it comes zero as a result. Now take the obtained number (from Step 1), i.e., 120, and again subtract the next odd number after 1, which is 3, → 120-3=117. Like this, we have to proceed further.
Step 3: now we have to count the number of subtraction steps it takes to yield 0 finally. Here, in this case, it takes 11 steps
So, the square root is equal to the count, i.e., the square root of 121 is ±11.
When we find the square root of 121, we often make some key mistakes, especially when we solve problems related to that. So, let’s see some common mistakes and their solutions.
Find √(121⤬36) ?
√(121⤬36)
= 11 ⤬6
= 66
Answer : 66
firstly, we found the values of the square roots of 121 and 36, then multiplied the values.
What is √121 multiplied by 4 ?
√121 ⤬ 4
= 11⤬4
= 44
Answer: 44
finding the value of √121 and multiplying by 4.
Find the radius of a circle whose area is 121π cm^2.
Given, the area of the circle = 121π cm2
Now, area = πr2 (r is the radius of the circle)
So, πr2 = 121π cm2
We get, r2 = 121 cm2
r = √121 cm
Putting the value of √121 in the above equation,
We get, r = ±11 cm
Here we will consider the positive value of 11.
Therefore, the radius of the circle is 11 cm.
Answer: 11 cm.
We know that, area of a circle = πr2 (r is the radius of the circle)According to this equation, we are getting the value of “r” as 11 cm by finding the value of the square root of 121.
Find the length of a side of a square whose area is 121 cm^2
Given, the area = 121 cm2
We know that, (side of a square)2 = area of square
Or, (side of a square)2 = 121
Or, (side of a square)= √121
Or, the side of a square = ± 11.
But, the length of a square is a positive quantity only, so, the length of the side is 11 cm.
Answer: 11 cm
We know that, (side of a square)2 = area of square. Here, we are given with the area of the square, so, we can easily find out its square root because its Square root is the measure of the side of the square
Find √121 / √100
√121/√100
= 11/10
= 1.1
Answer : 1.1
we firstly found out the values of √121 and √100, then divided .
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.
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