1) If the side length of a small square is x cm, the side length of a large square is 5+x cm (5+x) 2-x 2 = 95, and x=7 when solving the equation.

So the area of the big square =12x12 =144, and the area of the small square = 7 * 7 = 49 (X 2 represents the square of x, that is, x times x).

Method 2: The area of the shaded part is the difference between the two areas 95. Divided into two rectangles and a square, it is equal to the side length of two small squares multiplied by 5 plus the area of a square with a side length of 5, so the side length of the small square =(95-5×5)÷2÷5 = 7, and the side length of the large square =7+5= 12.

2) The shadow area is actually half of the parallelogram area, so it is 10 cm2. Because the sum of the areas of three triangles =? X height x (the sum of the bases of three triangles), the height is the height of a parallelogram, and the sum of the bases of three triangles is a base of a parallelogram, so the sum of the areas of three triangles =? Area of parallelogram

3) The area of ① =? S= 10X 10÷4=25 square centimeters.

② Area =25÷2= 12.5 cm2.

The area of ③ =? X5X2.5=6.25 square centimeters

Area of ④ = twice of ③ =12.5cm.

(5) area =2 times the area of (3) = 12.5 cm2,

4) Put the shaded parts together, it is still a rectangle with length = 18-3 = 15m and width = 12-3 = 9m, so the area = 15x9 = 135m.

Method 2: Shadow area = original area-parallelogram area-rectangle area+repeated subtraction middle small parallelogram area =12x18-18x3-12x3+3x3 =135m2.

5) Divide the shadow into many rectangles (the last one is a small square).

Area s = 2.4 * 0.3+(2.4-0.3) * 0.3+(2.4-0.3-0.3) * 0.3+(2.4-0.3-0.3) * 0.3+(2.4-0.3-0.3-).

=2.4*0.3+2. 1*0.3+ 1.8*0.3+ 1.5*0.3+ 1.2*0.3+0.9*0.3+0.6*0.3+0.3*0.3=0.3*(2.4+0.3)*8÷2=3.24