The perimeter of a square is equal to that of a circle. Given that the side length of a square is 3.14 cm, what is the radius of a circle? What's the area in square centimeter?

The perimeter of a square is equal to that of a circle. Given that the side length of a square is 3.14 cm, what is the radius of a circle? What's the area in square centimeter?

radius
3.14×4÷3.14÷2
=12.56÷3.14÷2
=2 cm
Area: 3.14 × 2 × 2 = 12.56 square centimeter

The perimeter of a square is equal to that of a circle. Given that the side length of a square is 3.14 cm, what is the radius and area of the circle?

Radius of circle = 3.14 × 4 △ 3.14 △ 2 = 2cm
Area = 2 × 2 × 3.14 = 12.56 square centimeter

Cut out the largest circle in a square piece of paper with an area of 8 square centimeters. How many square centimeters is the area of the circle

Divide the square into four small squares. The side length of each small square is the radius of the garden
Radius r = 8 / 4 under root = 2 under root
The area of the garden is s = 3.14 * (2 under the root sign) ^ 2 = 6.18 square centimeters

Cut a circle with the largest area from a square paper with a side length of 8 cm. What's the area of this circle? What's the remaining area?

The diameter of the largest circle is 8 cm and the radius is 8 / 2 = 4 cm
The area of this circle
=3.14*4*4
=50.24 square centimeter
The remaining area
=8*8-50.24
=64-50.24
=13.76 square centimeter

A fixed point of a square is the center of the circle, and its side length is the radius of the circle?

Radius of circle = 12.56 △ 3.14 △ 2 = 2 (CM)
Square area = 2 × 2 = 4 (square centimeter)

The area of a circle is 12.56 square decimeters

12 * r * r = 12. 56, r = 2
Then d = 4,
Let the side length of a square be a
Then a ^ 2 + A ^ 2 = 4 ^ 2
A ^ 2 = 8
So the area of the largest square is 8

The radius of a circle is 3cm, and its diameter is______ Cm, circumference is______ Cm, the area is______ cm2．

Diameter: 3 × 2 = 6 (CM), perimeter: 2 × 3.14 × 3 = 18.84 (CM), area: 3.14 × 32 = 28.26 (cm2), so the answer is: 6; 18.84; 28.26

The diameter of a circle increases from 5cm to 10cm, its perimeter is (), and its area is ()

Perimeter C = π d = π * 10 ≈ 31.4cm
Area s = π R & sup2; = π * (D / 2) & sup2; = π * 5 & sup2; = 78.5cm & sup2;

The diameter of a semicircle is 5cm, its circumference is () cm, and its area is () square cm

The diameter of a semicircle is 5 cm, its perimeter is (31.4) cm, and its area is (78.5) square cm

The radius of a circle is 3.5cm, its perimeter is () cm, and its area is () square cm? Build a circular fish pond with a diameter of 20m, and its floor area is () square meters
The radius of a circle is expanded three times, its perimeter is expanded () times, and its area is expanded () times
A circle with a circumference of 18.84cm has a radius of () and an area of () square centimeters

The radius of a circle is 3.5cm, its perimeter is (21.98) cm, and its area is (38.465) square cm
Build a round fish pond with a diameter of 20 meters, which covers an area of (314) square meters
The radius of a circle is expanded three times, its perimeter is expanded three times, and its area is expanded nine times
A circle with a circumference of 18.84 cm has a radius of (3 cm) and an area of (28.26) square cm