Question

Обчислити довжину кола і площу круга радіус якого дорівнює 4см

Answer 1

Дано:

r = 4см

Знайти: C, Sкр.

Розв'язання: C = 2πr

Sкр. = πr²

C = 2•3,14•4 = 25,12(см)

Sкр. = 3,14•16 = 50,24(см²)

Відповідь: 25,12 см; 50,24 см²

Answer 2

Calculating the Circumference and Area of a Circle with a Radius of 4cm

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

1. Circumference of a Circle (C): The circumference of a circle can be calculated using the formula: \[ C = 2 \pi r \] where \( r \) is the radius of the circle and \( \pi \) is a constant approximately equal to 3.14159.

2. Area of a Circle (A): The area of a circle can be calculated using the formula: \[ A = \pi r^2 \] where \( r \) is the radius of the circle and \( \pi \) is a constant approximately equal to 3.14159.

Calculations

1. Circumference: Using the formula \( C = 2 \pi r \), where the radius \( r \) is 4cm, we can calculate the circumference: \[ C = 2 \times 3.14159 \times 4 \] \[ C \approx 25.13272 \, \text{cm} \]

2. Area: Using the formula \( A = \pi r^2 \), where the radius \( r \) is 4cm, we can calculate the area: \[ A = 3.14159 \times 4^2 \] \[ A \approx 50.26544 \, \text{cm}^2 \]

So, for a circle with a radius of 4cm: - Circumference is approximately 25.13272 cm. - Area is approximately 50.26544 cm².