1. The side a square is m meters long. The length of a rectangle is 3 meters longer than the side of the square, and the width of the rectangle is 3 meters shorter than the side of the square. Which has a greater area? By how much?
Answers
Answer:
Let the width of rectangle is y cm then length of rectangle is y+8 cm
Then area of total rectangle =y(y+8)=y
2
+8ycm
2
If a square side x cm cut in this rectangle whose side is half of width of rectangle
So x=\frac{1}{2}y \Rightarrow y=2x$$
Then area of total rectangle =y(y+8)=y
2
+8ycm
2
put the value y=2x
Then area of rectangle=2x(2x+8)=4x
2
+16xcm
2
Then renaming area =4x
2
+16x−x
2
=(3x
2
+16x)cm
2
The area of the square is greater than the area of rectangle. It is greater by 9 units.
GIVEN
The side a square is m meters long. The length of a rectangle is 3 meters longer than the side of the square, and the width of the rectangle is 3 meters shorter than the side of the square.
TO FIND
Which has a greater area? By how much?
SOLUTION
We can simply solve the above problem as follows;
Let the side of the square = m meter
Length of the rectangle = m + 3 meter
Breath of the rectangle = m-3 meter
We know that,
Area of the square = Side × Side
Area of the square = m² metre. (Equation 1)
And,
Area of the rectangle = L × B
= (m-3)(m+3)
Applying the formula; (a+b)(a-b) = a² - b²
= m²- 9 meters (Equation 2)
From 1 and 2
We can observe that, The area of the square is greater. It is greater by 9 units.
, The area of the square is greater. It is greater by 9 units. #Spj2