The width of the rectangular field is 18m and it is 4 times less than the length, find the area and perimeter of this field.

Let’s find the length of the rectangular field.
Since the field width given by the condition is 4 times less than the length, it means that the length is 4 times greater than the width, respectively, then:

a = b * 4 = 18 * 4 = 72 (m).

The area of ​​a rectangle is found as the product of its length and width, then the area of ​​a rectangular field with a length of 72 m and a width of 18 m will be:
S = a * b = 72 * 18 = 1296 (m ^ 2).

The perimeter of a polygon is equal to the sum of the lengths of all its sides. Hence, the perimeter of the rectangle is:
P = a + b + a + b = 2 * a + 2 * b = 2 * (a + b) (since the opposite sides of the rectangle are equal).

Find the perimeter of the rectangular field:

P = 2 * (72 + 18) = 2 * 90 = 180 (m).

Answer: S = 1296 m ^ 2; P = 180 m.