Question 704634
let x be the length 
x-18 is the width 

area = length * width
2480= x(x-18)

2480 = x^2-18x
x^2-18x-2480=0

a=	1    	b=	-18	c=	-2480		
							
b^2-4ac=	324	-	-9920				
b^2-4ac=	10244		{{{sqrt(	10244	)}}}=	101.21	
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}							
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}				)/			
x1=(	18	+	101.21	)/	2		
x1=	59.61						
x2=(	18	-	101.21	)/	2		
x2=	-41.61						
Ignore negative value							
x	=	59.61	m

width / height = 59.61-18
height = 41.61	m