Answer :
[tex]Perimeter\ of\ rectangular\ deck=2width+2lenght\\\\
length=4width\\\\
30=2width+2(4width)\\\\
30=2width+8width\\\\
30=10width\ \ \ \ |divide\ by\ 10\\\\
width=3feet\\\\
Area=width*length\\\\
Area=3*4=\boxed{12feet^2}[/tex]
36 square feet because the width would be a and so since the length is 4 times that you can say that the two sides added together would be 5a
30 feet is the parameter which would include all 4 sides but we are only looking for 2 sides so you can divide that by 2 so
5a=15 so divide 15 by 5 and you get 3 so a=3
4a=4*3= 12=length
a=3=width
length*width=area
12*3= 36 square feet
30 feet is the parameter which would include all 4 sides but we are only looking for 2 sides so you can divide that by 2 so
5a=15 so divide 15 by 5 and you get 3 so a=3
4a=4*3= 12=length
a=3=width
length*width=area
12*3= 36 square feet
