Made of a rectangle with a width of 1.8 dm. , and the length is 1.4 times

Made of a rectangle with a width of 1.8 dm. , and the length is 1.4 times the width, a square with a side of 0.9 dm was cut out. Find the area of the remaining shape.

We find the area of the rectangle by the formula:
S1 = a * b.
By condition, we know the width, we find the length, which is 1.4 times the width:
a = 1.4 * b = 1.4 * 1.8 = 2.52 (dm²).
Find the area of the rectangle:
S1 = 2.52 * 1.8 = 4.536 ≈ 4.54 (dm²).
The side of the cut-out square is known by the problem statement, we find the area of the square by the formula:
S2 = a² = 0.9² = 0.81 (dm²).
The area of the remaining figure is:
S = S1 – S2 = 4.54 – 0.81 = 3.73 (dm²).
Answer: the remaining figure has an area of 3.73 dm².