There is a semicircular flower bed, its perimeter is 102.8 cm, area?

There is a semicircular flower bed, its perimeter is 102.8 cm, area?

102.8 divided by 5.14 is the radius
20 * 20 * 3.14 divided by 2 equals the area of the semicircle

It is known that the perimeter of a semicircular flowerbed is (5 π + 10) m, then the area of the semicircular flowerbed is ()
A. 10 π M2 b.25 π M2 C. (25 / 2) π M2 d.50 π M2

It should be B

The circumference of a semicircular piece of paper is 10.28 cm. How many square centimeters is the area of this piece of paper?

Radius = 10.28 ÷ (3.14 + 2) = 2cm area = 2 × 2 × 3.14 × 1 / 2 = 6.28cm2

A semicircle of paper, the area is 157 square centimeters, its circumference is () cm
Content of Cixi Yucai junior high school entrance examination in 2007

Let the radius of the semicircle be r and the circumference be l, in cm
Its area 157 = 3.14 x R △ 2
R = 10 cm
So perimeter L = 2R + 3.14r = 51.4cm

The area of a semicircular piece of paper is 234 square centimeters. Find the circumference of this piece of paper (accurate to 0.1 cm)
worry

Because it is a semicircle, the area of the circle is 468
According to the formula, 468 = π R2
r2=468π
R = 468 π under radical
Because l = 2 π R
So 468 π =? Under L = 2 * π * radical?
And because it's a semicircle
So 468 π =?

The area of a semicircular piece of paper is 18 π square centimeter

∵ area of semicircle = 18 π#178; ∵ area of whole circle = 18 π × 2 = 36 π#178; ∵ area of circle s = π r#178; ∵ r = 6 and∵ circumference of circle C = 2 π R ∵ C = 12 π and∵ circumference of semicircle = 1 / 2 circumference + diameter ∵ C semicircle = 1 / 2 · 12 π + 12 = 6 π + 12

The area of a semicircle paper is 156cm square. Find the perimeter of the paper

"The coast loves to sleep":
The area of half circle is 156cm & sup2;, and that of full circle is 156cm & sup2; × 2 = 312cm & sup2;
The square of its radius is 312cm & sup2; △ 3.14 = 99.36cm & sup2; ≈ 100cm & sup2;
Its radius is √ 100cm & sup2; = 10cm
Its diameter is 20 cm
Its circumference is 20cm × 3.14 = 62.8cm
What grade are you in? I know you can do it yourself. I just want to see if what others do is the same as you
Well, now you can rest assured. Good luck and goodbye

The radius of a circle is 6cm, its circumference is () cm, and its area is () square cm

2*3.14*6=37.68
3.14*6*6=113.04
The radius of a circle is 6 cm, its circumference is (37.68) cm, and its area is (113.04) square cm

A circle is increased from 5cm to 10cm, its perimeter is increased by several centimeters, and its area is increased by several square centimeters

Do you know how to review the textbook and remember the formula of perimeter and area. Perimeter C = 2 π r = π D. area s = π R & sup2;. D = 2R. Go to the textbook and find these two formulas

When a circle is enlarged, its area is eight times larger and its circumference is 50.24 cm larger than the original. The original area of the circle is______ Square centimeter

50.24 △ 3.14 △ 2 = 8 (CM); 8 + 1 = 9, 9 = 3 × 3, 3-1 = 2, 8 △ 2 = 4 (CM); 3.14 × 42, = 3.14 × 16, = 50.24 (CM); answer: the original area of this circle is 50.24 square cm, so the answer is 50.24