Question

Вычислите длину окружности , радиус которой равен 10 см. , 20 см. , 1 м. вычислите площадь круга , радиус которого равен 10дм.,20 дм.,1 м. если можно то объясните мне как решать подобные задачи пожалуйсто

Answer 1

1:
$R_{1}$ = 10 см                       С=2$\pi$R  
$R_{2}$ =20 см                        1)$С_{1}$ = 2 * 3,14 * 10=62.8(СМ)
$R_{3}$ =1 метр                      2)$С_{2}$=2*,14 *20=1256(СМ)
$С_{2}$=?см                           3)$С_{3}$=2 *3,14 * 1 = 6,28(дм)
$С_{2}$=?см
$С_{3}$=?метр                       ответ:


2)$R_{1}$=10 дм                      S=$\pi$R2
$R_{2}$=20 дм                          $S_{1}$=3,14 * 100=3,14
$R_{3}$=1м                               $S_{2}$=3,14 *400=12,560
$S_{1}$=?дм                             $S_{3}$=3,14 *1=3,14
$S_{2}$=?дм                       
$S_{3}$=?м                               ответ:

Answer 2

Calculating the Circumference and Area of Circles

To calculate the circumference and area of circles, we can use the following formulas:

1. Circumference (C): The circumference of a circle with radius r is given by the formula: \[ C = 2 \pi r \]

2. Area (A): The area of a circle with radius r is given by the formula: \[ A = \pi r^2 \]

Let's calculate the circumference and area for circles with radii of 10 cm, 20 cm, and 1 m.

Calculating the Circumference

1. For a circle with a radius of 10 cm: - Circumference \( C = 2 \pi \times 10 \) cm - \( C = 20 \pi \) cm

2. For a circle with a radius of 20 cm: - Circumference \( C = 2 \pi \times 20 \) cm - \( C = 40 \pi \) cm

3. For a circle with a radius of 1 m (100 cm): - Circumference \( C = 2 \pi \times 100 \) cm - \( C = 200 \pi \) cm

Calculating the Area

1. For a circle with a radius of 10 dm (100 cm): - Area \( A = \pi \times 100 \) dm\(^2\) - \( A = 100 \pi \) dm\(^2\)

2. For a circle with a radius of 20 dm (200 cm): - Area \( A = \pi \times 200 \) dm\(^2\) - \( A = 400 \pi \) dm\(^2\)

3. For a circle with a radius of 1 m (100 cm): - Area \( A = \pi \times 100 \) m\(^2\) - \( A = 100 \pi \) m\(^2\)

Conclusion

So, the calculated circumferences and areas for circles with different radii are as follows: - Circumference: 20π cm, 40π cm, 200π cm - Area: 100π dm\(^2\), 400π dm\(^2\), 100π m\(^2\)

This is how we can calculate the circumference and area of circles using the given radii. If you have any further questions or need more explanations, feel free to ask!