let

l = 20 cm the length of the rectangle

b = the breath of the rectangle

P = the perimeter of the rectangle

A = the area of the rectangle

Its breath is 1/4 cm shorter than the length:

b = l - 1/4

b = 20 - 1/4

b = 79/4 cm

the formula for the perimeter of a rectangle is:

P = 2(l + b)

P = 2(20 + 79/4)

P = 79.5 cm

the perimeter of the rectangle is 79.5 cm.

the formula for the are of a rectangle is:

A = l*b

A = 20*(79/4)

A = 395 cm^2

the area of the rectangle is 395 cm^2.