Respuesta :
The given numbers are 13, 27, 81, 21,43, 48,23,39,45.
Square number is that number which is a perfect square means if you multiply a number by itself the number you obtained is a perfect square i.e it's square root is a natural number.
√13=not a natural number
√27=√3×√3×√3=3√3=irrational number
√81=√9×√9=9=a natural number
√21=not a natural number
√43=not a natural number
√48=4√3=not a natural number
√23=not a natural number
√39=not a natural number
√45=3√5=not a natural number
So, out of following numbers 13 27 81 21 43 48 23 39 45→81 is the only square number.
Answer:
Option 3 - 81
Step-by-step explanation:
Given : Numbers 13, 27, 81, 21, 43, 48, 23, 39, 45.
To find : What is the square number from given numbers ?
Solution :
Square number is defined as it is the product of some integer with itself.
To find the square number we have to take root of each number,
1) [tex]\sqrt{13}=3.60[/tex]
Not a square number.
2) [tex]\sqrt{27}=5.19[/tex]
Not a square number.
3) [tex]\sqrt{81}=9[/tex]
It is a square number.
4) [tex]\sqrt{21}=4.58[/tex]
Not a square number.
5) [tex]\sqrt{43}=6.55[/tex]
Not a square number.
6) [tex]\sqrt{48}=6.92[/tex]
Not a square number.
7) [tex]\sqrt{23}=4.79[/tex]
Not a square number.
8) [tex]\sqrt{39}=6.24[/tex]
Not a square number.
9) [tex]\sqrt{45}=6.70[/tex]
Not a square number.
Therefore, Option 3 is a rational number.
