Definition
Example
Square root - a number that The square root of 25 is 5,
produces a specified quantity since 5 x 5 = 25.
when multiplied by itself.
Perfect square or Square
number – A number that is
the square of an integer.
Radical expression – An
expression involving a radical
sign.
9 is a perfect square
because 9 = 32
36
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Notes
Finding Square Roots
Square Root – A number which, when multiplied by
itself, results in another number.
 52 = 25
So, the square root of 25 is 5.
We write it:

25  5
Perfect Squares
Perfect square – A number that is a square of a
whole number.
 Can be represented by arranging objects in a
square.
You need to memorize the first 15 perfect squares.
Lets find them…
Squared
Perfect
Square
Square
Root
Squared
Perfect
Square
Square
Root
12 =
1
√1=1
92 =
81
√81=9
22=
4
√4=2
102 =
100
√100=10
32 =
9
√9=3
112 =
121
√121=11
42 =
16
√16=4
122 =
144
√144=16
52 =
25
√25=5
132 =
169
√169=13
62 =
36
√36=6
142 =
196
√196=14
72 =
82 =
49
64
√49=7
√64=8
152 =
225
√225=15
81
 169
37
.
37
Since 37 is not a perfect square, we have to use another
method to calculate it’s square root.
Most numbers are NOT perfect squares and their
solutions are not whole numbers.
1) 49
2) 121
3) 3600



4) .
900
5) .
 196
6) .
 16
7) .


8) . A
A  4m 2
 256cm 2


9) .
16z
10).
x 2  y 2  20


11).
3b 2  75
12).
15  d 2  96