The area of a circle is 78.5 square centimeters. Divide it into 16 parts. What are the small fan-shaped area and perimeter of each part

The area of a circle is 78.5 square centimeters. Divide it into 16 parts. What are the small fan-shaped area and perimeter of each part

Area per unit
78.5÷16=?
radius
78、5÷3.14=25
5x5 = 25, so the radius is 5
Circumference 3.14x5x2 = 31.4
Each segment has a circumference of 31.4 △ 16 + 5x2

Divide a circle into 32 parts, one of which is further divided into two parts to form a rectangle, which is 16cm longer than the circumference of the circle. Calculate the area of the circle

When the circumference is increased by 16cm, the radius of the circle is 16 / 2 = 8cm
(Note: the circumference of a rectangle is actually two wider than that of a circle, and the width is equal to the radius of the circle.)
Area of circle = π * 8 ^ 2 = 200.96 square centimeter

After dividing a circle into two identical semicircles, their circumference increases by 6cm. What is the circumference of the original circle? What is the area?

Radius 6 △ 2 △ 2 = 1.5cm
Perimeter 3.14 × 2 × 1.5 = 9.42 cm
Area: 3.14 × 1.5 × 1.5 = 7.065 square centimeter

Divide a circle into two semicircles. The circumference of the semicircle is more than that of the circle

Add 2D, that is, add two diameters

The diameter of a semicircle is 16 cm. What is the area and perimeter of the semicircle?

The area of this semicircle is half that of a circle of the same diameter
namely
3.14*8*1/4
The circumference is half of the circumference of a circle of the same diameter plus the diameter
16+3.14*16
Do it yourself

After a circle is divided into several small sectors averagely, it is put together into an approximate rectangle, and its perimeter is increased by 10 cm

The two long sides of the rectangle are the circumference of the circle, and the extra 10 cm is the two radii of the circle, so the radius of the circle is 5 cm, s = 25 π

Cut a round piece of paper into two equal semicircles. Their circumference has been increased by 10 cm. What is the area of this circle?

"Good girl Ye - level 2":
After a circle is cut into two semicircles, the circumference increases by two diameters, so we know the diameter of the circle is
The radius is 5cm △ 2 = 2.5cm
Circle area = (2.5cm) & sup2; × 3.14 = 19.625cm & sup2;
A: the area of the original circle is 19.625 square centimeters
Good luck and goodbye

The circumference of a rectangular paper is 28cm, and the ratio of length to width of the rectangle is 5:2. Cut the largest circle from the paper, and the area of the circle is______ Square centimeter

The width of the rectangle: 28 ／ 2 × 25 + 2 = 14 × 27 = 4 (CM) the area of the circle: 3.14 × (4 ／ 2) 2 = 3.14 × 4 = 12.56 (square cm) a: the area of the circle is 12.56 square cm. So the answer is: 12.56

Cut a maximum circle with a circumference of 18.84 cm from a piece of square paper, and calculate the area of the paper scraps to be cut?

18.84 ﹣ 3.14 = 6 (CM), 6 ﹣ 2 = 3 (CM), 6 × 6-3.14 × 32, = 36-3.14 × 9, = 36-28.26, = 7.74 (cm2). Answer: the area of paper scraps is 7.74 square cm

There is a biggest circle in the square. The circumference of the circle is 18.84 decimeters. What is the circumference of the square?

18.84 △ 3.14 = 6 (decimeter) 6 × 4 = 24 (decimeter)