PSAT Math : Squares
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Example Questions
Example Question #3 : How To Find The Area Of A Square
The perimeter of a square is 
The perimeter of a square is given by 
So the area of the new square is given by 
Example Question #11 : Squares
A half circle has an area of 
108
144
36
72
81
144
If the area of the half circle is 
Use the formula for the area of a circle to solve for the radius:
36π = πr2
r = 6
If the radius is 6, then the diameter is 12. We know that the sides of the square are the same length as the diameter, so each side has length 12.
Therefore the area of the square is 12 x 12 = 144.
Example Question #1 : How To Find The Length Of The Side Of A Square
The area of square R is 12 times the area of square T. If the area of square R is 48, what is the length of one side of square T?
4
2
1
16
2
We start by dividing the area of square R (48) by 12, to come up with the area of square T, 4. Then take the square root of the area to get the length of one side, giving us 2.
Example Question #12 : Squares
When the side of a certain square is increased by 2 inches, the area of the resulting square is 64 sq. inches greater than the original square. What is the length of the side of the original square, in inches?
15
18
17
16
14
15
Let x represent the length of the original square in inches. Thus the area of the original square is x2. Two inches are added to x, which is represented by x+2. The area of the resulting square is (x+2)2. We are given that the new square is 64 sq. inches greater than the original. Therefore we can write the algebraic expression:
x2 + 64 = (x+2)2
FOIL the right side of the equation.
x2 + 64 = x2 + 4x + 4
Subtract x2 from both sides and then continue with the alegbra.
64 = 4x + 4
64 = 4(x + 1)
16 = x + 1
15 = x
Therefore, the length of the original square is 15 inches.
If you plug in the answer choices, you would need to add 2 inches to the value of the answer choice and then take the difference of two squares. The choice with 15 would be correct because 172 -152 = 64.
Example Question #622 : Geometry
If the area of a square is 25 inches squared, what is the perimeter?
10
Not enough information
20
15
25
20
The area of a square is equal to length times width or length squared (since length and width are equal on a square). Therefore, the length of one side is 
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