At the site below,
href="http://i91.photobucket.com/albums/k305/Suger_Pie/dafds.jpg">http://i91.photobucket.com/albums/k305/Suger_Pie/dafds.jpg,
we
notice a trapezium whose base is streteched equally about the origin 3 units on either
sides of the origin along the x axis.
If we go up from
along the y axis by 3 units we see the other parallel side of the trapezium which
streches by 2 units on either side of the y axis (perpenducular to y axis and || to x
axis.
The shade part is the area of the trapezium with
vertices at A(-3 , 0) , B(3,0), C(2 , 3) and D(-2,3).
The
area of the trapezium = (1/2)(sum of parallel sides)(distance between the paralle sides)
= (1/2){(3+3)+(2+2)}(3) =15.
The inequality here we can try
to make out is :
Area of the trapezium ABCD <
area of the outer rectangle with vertices at (-3,0) , (3,0), ( 3,3) and (-3,3) = 6*3 =
18 sq unit.
The area of the trapezium ABCD > Area of
the inner rectangle with vertices at (-2,0) ,(2,0), (2,3) and (-2,3) = 4*3 = 12
sqrt.
Of course the average of are inner and outer
rectangles = (18+12)/2 = 15 sq units = area of the trapezium
ABCD.
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