What is the area of a semicircle with a circumference of 10.28 cm

What is the area of a semicircle with a circumference of 10.28 cm

The radius is r
2r+πr=10.28
5.14r=10.28
r=2
The area is
14 × 2 & # 178; △ 2 = 6.28 (square centimeter)

A semicircle with a diameter of 10 cm has a circumference of () cm and an area of () square cm
A semicircle with a diameter of 10 cm has a circumference of () cm and an area of () square cm
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The radius of a circle is expanded to 2 times of the original, its perimeter is expanded to () times of the original, and its area is expanded to () times of the original
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The vertical row is called () and the horizontal row is called () to determine which column is generally from () to ()
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1. Same size 2. Square size 3. Circle size
If the small circle is directly 4cm and the radius of the big circle is 4cm, then the area of the small circle is ()
A. 1 in 16 B. 1 in 2 C. 1 in 4

A semicircle has a diameter of 10 cm, its perimeter is (31.4) cm, and its area is (78.5) square cm. Use a compass to draw a circle with a perimeter of 28.26 cm, and the distance between the two feet of the compass is (4.5) cm. The area of the circle is (63.585) square cm. The radius of a circle is twice the original, and its perimeter is enlarged

Use a semicircle paper with a circumference of 10.28 cm to make a large cone and find the bottom area of the cone

Semicircle radius = height = 10.28 ÷ (2 + 3.14) = 2cm
Arc = 2 × 2 × 3.14 × 1 / 2 = 6.28cm
Bottom radius = 6.28 △ 3.142 = 1cm
Cone bottom area = 1 × 1 × 3.14 = 3.14 square centimeter

A semicircle with a circumference of 10.28 cm, calculate its area

A semicircle with a circumference of 10.28 cm, calculate its area
3.14R+2R=10.28
R=2
Area = 3.14 * r * r / 2 = 6.28

The circumference is 15.42 cm semicircle, calculate the area

Radius: 15.42 ÷ (3.14 + 2) = 3cm
Area: 3.14 × 3 × 3 △ 2 = 14.13 square centimeter

If the radius of a semicircle is r, its circumference can be expressed as______ Its area can be expressed by______ If the circumference of the semicircle is 15.42 cm, the diameter of the semicircle is______ Cm, the area is______ Square centimeter

If the radius of a semicircle is r, its perimeter can be expressed as π R + 2R, and its area can be expressed as π R2 △ 2; let the diameter of the circle be DCM, D + 3.14 × D △ 2 = 15.42, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 2.57d = 15.42, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; d = 15.42 △ 2.57, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; D = 6, radius is 6 ／ 2 = 3 (CM), 3.14 × 32 ／ 2, = 3.14 × 9 ／ 2, = 14.13 (square cm), so the answer is: π R + 2R, π R2 ／ 2; 6, 14.13

The circumference of the semicircle is 10.28 cm. What is the area of the semicircle?

Let the radius of this semicircle be r, 2 × 3.14 × R ÷ 2 + 2R = 10.28, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 3.14r + 2R = 10.28, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 5.14r = 10.28, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; R = 2; the area of the semicircle: 3.14 × 22 △ 2, = 3.14 × 4 △ 2, = 12.56 △ 2, = 6.28 (square centimeter); a: the area of the semicircle is 6.28 square centimeter

The circumference of the semicircle is 10.28 cm. What is the area of the semicircle?

Let the radius of this semicircle be r, 2 × 3.14 × R △ 2 + 2R = 10.28, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 3.14r + 2R = 10.28, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & 5.14r = 10.28, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp

The circumference of a semicircle is 20.56 decimeters

Let the radius of the semicircle be r
2r+1/2*π*2r=20.56
r（2+π）=20.56
r=20.56/5.14
r=4
S = 1 / 2 * π * r & # 178; = 8 π = 25.12 decimeters & # 178;

Use 15.42 decimeter long wire to form a semicircle. The diameter of the semicircle is ()

Diameter = 15.42 ÷ (3.14 × 1 / 2 + 1) = 6dm