6. The diagonal of a rectangular field is 60
metres more than the shorter side. If the longer side is 30 metres more than
the shorter side, find the sides of the field. 7. The difference of
squares of two numbers is 180. The square of the smaller number is 8 times the
larger number. Find the two numbers.
Let shorter side = x m
Given that diagonal of a
rectangular field is 60 metres more than the shorter side
So diagonal will = x + 60 m
Given that the longer side is 30 metres more
than the shorter side
Longer side = x + 30 m
All angles in rectangle is always = 90 so
that we can Use Pythagoras theorem
Diagonal 2 =
shorter side 2 + longer side 2
Plug the values In this formula we get
(x+60)2 = (x)2 + (x+30)2
Now use the formula (a+b)2 = a2 +b2 +2ab
We get
x2 + 120 x + 3600 = x2 + x2 + 60 x +
900
subtract x`2
+ 120 x + 3600 both side we get
0 = x2 - 60 x - 2700
Factorize it now
x 2 - 90 x + 30 x – 2700 = 0
x ( x - 90 ) + 30 (x – 90 )=0
( x – 90 ) (x + 30 ) = 0
x- 90 = 0 or x + 30 = 0
x = 90
or x = - 30 any side of rectangle
cannot negative
so shorter side = x + 30
= 90 + 30 = 120
Diagonal is = x + 60 = 90
+ 60 = 150
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