Solution :
Let x be the length of garden and y be its width.
Then,
According to question, perimeter = 2(length +width) = 2(x + y)
Therefore, half perimeter = (x + y)
But it is given as 36
\(\therefore\) (x + y) = 36
Also, x = y + 4
Now, we form the table given below for both the equations to find the solutions graphically.
For equation, x + y = 36
If x = 20, y =16
If x = 24, y = 12
x
20
24
y
16
12
For equation, x โ y = 4
If x = 10, y = 6
If x = 16, y = 12
x
10
16
y
6
12
Now plot the points in the table on the graph.
We see that lines intersect at point (20,16) as shown in the graph.
Hence, Length = 20 m and width = 16 m