Buzz
Calculating the circumference of a circle is quite straightforward. With this article, we introduce calculation formulas and delve into intriguing insights about the constant pi that we frequently use. Let's explore how fascinating these concepts can be!
How to calculate the circumference of a circle using which formula?
How is the circumference of a circle calculated?
- Formula for calculating the diameter of a circle:
d = 2r (1)
- The formula for calculating the circumference of a circle is as follows:
C = d * π = 2 * r * π (2)
Where:
C represents the circumference of the circle
d is the diameter
r is the radius
π = 3.14
- Stated verbally:
+ The circumference of a circle is the product of its diameter and pi.
Or:
+ The circumference of a circle is the product of twice the radius and pi.
* Application Exercise: Calculate the circumference of a circle given:
a) r = 5 cm
b) r = 4.6 cm
c) d = 7 cm
d) d = 8.3 cm
* Hint:
- Use formula (1) to solve parts a and b
- Use formula (2) to solve parts c and d
Interesting facts you may not know about the number pi (π)
1. Definition
- Pi (π) is a mathematical constant, defined as the ratio of the circumference of a circle to its diameter.
- The name pi originates from the Greek word peripheria, meaning the circumference of a circle.
- Pi is an irrational number. (An irrational number is a real number that cannot be expressed as a finite or repeating decimal, and the set of irrational numbers is uncountable.)
2. History of pi
- Pi (π) is named after the 16th letter of the Greek alphabet.
- Time of emergence: Pi appeared in the 18th century
- Pi is not just a simple computational constant; for the field of Mathematics, it encapsulates the entire history of ancient mathematics dating back to 4000 years.
3. Determining the value of pi
- To determine the value of pi in any circle, we simply need to measure the circumference and diameter, then divide the circumference by the diameter, and we will get the result π = 3.1415....
4. Fascinating facts about pi
- The number π was initially discovered by ancient Babylonians, followed by the Egyptians,...
- The first approximate value of pi was calculated as 3.1605.
- The first mathematician to compute pi was the world-renowned mathematician Archimedes, using the Pythagorean theorem.
- The symbol π was introduced in 1706 by the English mathematician William Jones, using the value 3.14159 .
- Pi has no exact value because it is an irrational number; the more digits of pi we calculate, the better.
+ The number pi holds the Guinness World Record for having over 67,000 digits, calculated by Chinese mathematician Lu Chao.
+ A website named PI-search Page, aided by computer software, computed pi to 200 million decimal places.
- March 14th is designated as Pi Day and July 22nd as Approximate Pi Day - these are two special days dedicated to the mathematical constant pi.
With the basic knowledge of the circumference of a circle and intriguing facts about pi presented here, we hope to aid students in memorizing calculation formulas and enriching their understanding of the issue. Additionally, students should pay attention to calculating the area of a circle, circumference and area of a semicircle. These formulas are also crucial in their curriculum.
- Read more: Formulas for calculating perimeter and area of a semicircle
Furthermore, once the circumference of a circle is calculated, students can readily apply it to find the area of the circle. They can refer to exercises on calculating the area of a circle given circumference c=28.26m shared on Mytour.
