The area and perimeter of a square, if its side is 1m.9cm.

1m 9cm = 1.09m
1. The perimeter of the square P is equal to the sum of all its sides a, the square has 4 of them, therefore: P = 4a = 4 • 1.09m = 4.36m
2. The area of the square S is equal to the product of its two sides a, therefore S = a • a = 1.09 • 1.09 = 1.1881m ^ 2
Answer: 4.36m; 1.1881m ^ 2
OR
If we mean one square 1m and another square 9 cm, then
1) P = 4 • a = 4 • 1 = 4m
S = a • a = 1 • 1 = 1 m ^ 2
2) P = 4 • 9 = 36 cm
S = a • a = 9 • 9 = 81 cm ^ 2
Answer: 4m; 1 m ^ 2; 36 cm; 81 cm ^ 2