One side of the rectangle is 12 mm and the other 5 mm smaller. Find the perimeter and area of the rectangle.

1. Calculate the length of the other side of the rectangle:

12 – 5 = 7 millimeters.

2. We calculate the total length of all sides of a given geometric figure – perimeter (P):

P = 2 x 12 + 2 x 7 = 38 millimeters.

3. Calculate the area of a given rectangle (S):

S = 12 x 7 = 84 millimeters².

Answer: the area of a given rectangle is 84 millimeters², its perimeter is 38 millimeters.