The perimeter of a rectangular piece land is 130m and its area is 1000sq.m find it's dimensions.
please give step by step explanation
Answers
Length = l m
Breadth = b m
Perimeter = 130 m
2 ( l + b ) = 130
l + b = 65 -----( 1 )
Area = 1000 m²
lb = 1000 ---( 2 )
( l - b )² = ( l + b )² - 4lb
= ( 65 )² - 4 × 1000
= 4225 - 4000
= 225
l - b = √ 225
l - b = 15 -----( 2 )
Add ( 1 ) and ( 2 ) equations , we get
2l = 80
l = 40 m
Put l = 40 in equation ( 2 ) , we get
40 × b = 1000
b = 1000/40
b = 25 m
Therefore ,
l = 40 m
b = 25 m
I hope this helps
Step-by-step explanation:
perimeter of a rectangle is 2(l+b) .
2(l+b) = 130_____(1)
l+b =130/2
l+b =65
l = 65 -b______(2)
Area of rectangle is l×b.
l×b =1000_____(3)
Substitute l=65-b in equation (3)..
(65-b)×b =1000
65b -b^2 =1000
b^2-65b +1000 = 0
b^2- 40b - 25b +1000 =0
(b-40)(b-25) =0
b=40 or 25
substitute b=25 in equation (2)
l = 65 - 25
l = 40
Length =40cm and breadth = 25cm.