Question

Диаметр круга 4 см.Найдите площадь этого круга и длину окружности,которая его ограничивает.Ответ округли до сотых.(≈3,14)Помогите проблемы с матиматикой

Answer 1

Площадь круга по формуле
S = π*D²/4 = π*R²
S = π16/4 = 4π = 3.14*4 ~ 12.56 см²- ОТВЕТ
Длина окружности
L = π*D = 2*π*R
L = 4π = 12.56 см~ ОТВЕТ

Answer 2

Calculating the Area and Circumference of a Circle

To find the area and circumference of a circle with a diameter of 4 cm, we can use the following formulas:

1. Area of a Circle: - The formula to calculate the area of a circle is: A = πr^2, where A is the area and r is the radius of the circle. - Since the diameter is given, we can find the radius using the formula: r = d/2, where d is the diameter.

2. Circumference of a Circle: - The formula to calculate the circumference of a circle is: C = 2πr, where C is the circumference and r is the radius of the circle.

Let's calculate the area and circumference using the given diameter of 4 cm.

Calculations

1. Radius Calculation: - The radius r can be calculated using the formula: r = d/2. - For a diameter of 4 cm, the radius is: r = 4/2 = 2 cm.

2. Area Calculation: - Using the formula A = πr^2, where r = 2 cm: - A = π * (2)^2 - A = 4π square centimeters.

3. Circumference Calculation: - Using the formula C = 2πr, where r = 2 cm: - C = 2π * 2 - C = 4π centimeters.

Therefore, for a circle with a diameter of 4 cm: - The area is approximately 4π square centimeters. - The circumference is approximately 4π centimeters.

Final Answers

- Area: Approximately 4π square centimeters (≈12.57 square centimeters). - Circumference: Approximately 4π centimeters (≈12.57 centimeters).