In the figure below, it is known that the area of a square is 40 square centimeters, so how many square centimeters is the area of a circle in the figure

In the figure below, it is known that the area of a square is 40 square centimeters, so how many square centimeters is the area of a circle in the figure

Circle radius = root 40 / 2 = root 10
Circle area = 3.14 * square of root 10 = 31.4 square centimeter

As shown in the figure on the right, the area of a square is 40 square centimeters, and the area of a circle is () square centimeters
The picture is: a circle, a quarter is a square, known square area is 40 square centimeters

3.14 times 40 = 125.6

As shown in the figure on the right, we know that the area of a square is 40 square centimeters, so we can find the area of a circle
There is a circle outside the square. Find the area of the circle

Connect the two diagonals of the square, divide the square into four right angles equally, and the sides are isosceles right triangles of radius
40 △ 4 = 10 cm and 178;, the area of each right triangle is 10 cm and 178;
10 × 2 = 20 cm and 178;, the product of two right angle sides is 20 cm and 178;, that is, the square of radius is 20 cm and 178;
14 × 20 = 62.8 cm and 178; the area of circle is 62.8 cm and 178;

As shown in the figure below, the area of the shadow is 8 square centimeters, and the area of the circle is calculated
The figure is: draw a square in a circle, then divide the square into four parts equally, then one part is a triangle, the area of the shadow part is a triangle, the area of the triangle = 8 square centimeter

That is to say, the area of isosceles right triangle with radius as side is 8 square centimeters, that is R ^ 2 / 2 = 8
The area of the circle is π R ^ 2 = 16 π