Answer:
Area of the new rectangle = 148.8 cm square
Step-by-step explanation:
Let x be the dimensions of the rectangle then the
Perimeter of the Original rectangle= 2(L+B)
= 2 ( 3x+2x) = 2(5x)= 10xcm
If the length is increased by eight the new length would be 3x+ 8
and width would be 2x+x= 3x after 50 % increase
Perimeter of the new rectangle= 2(L+B)
= 2 ( 3x+8 +3x)
= 2 (6x+8)
= 12x + 16
Ratio of the new perimeter to the original perimeter is
New perimeter : Original perimeter
8 : 5
12x+ 16 : 10x cm
80x= 60x + 16
20x= 16
x= 16/20= 4/5
Putting the value of length and breadth in place of x
Area of the new rectangle = L*B = 3 * (4/5) +8 *3(4/5)=
= 12+ 40/5 * 12/5
= 62/5* 12/5
= 744/5
= 148.8 cm square