Question 899025
let width be x
length = (x+4)

it is a right triangle

(1/2)x*(x+4)=99

multiply by 2
x(x+4)=198

x^2+4x=198
x^2+4x-198=0

solve quadratic 

Find the roots of the equation by quadratic formula							
							
Find the roots of the equation by quadratic formula							
							
a=	1	,	b=	4	,	c=	-198
							
b^2-4ac=	16	+	792				
b^2-4ac=	808						
{{{	sqrt(	808	)=	28.43	}}}		
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}							
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}							
x1=(	-4	+	28.43	)/	2		
x1=	12.21						
{{{x2=(-b-sqrt(b^2-4ac))/(2a)}}}							
x2=(	-4	-28.43	) /	2			
x2=	-16.21						
Ignore negative value							
x=	12.21	

12.21 & 16.21