Posts Tagged ‘circumference’
Tuesday, November 17th, 2009
Overview of Half-Circles
Description
A detailed tutorial on equations of a half-circle. Step by step tutorial including several examples and an explanation of half-circles for reference.
Overview
A half-circle is truely half of a circle. If you take a circle and cut it in half, you will get a half circle. Because of this, the equations of the half-circle are very similar to the equations of a full circle – simply divide the equation by two. The only ones that you cannot find that way are the radius, diameter, and circumference. The radius and diameter do not change on a half-circle. There is no circumference on the half-circle, but if you need the circumference for another formula you can use the circumference of the whole circle of that half-circle.
Tags: area, basic, circle, circumference, coordinates, cut, diameter, divide, equation, Geometry, half, half-circle, pi, radius, shape, split, two, whole
Posted in Geometry | No Comments »
Tuesday, November 10th, 2009
An Overview of Pi
Description
A detailed tutorial on what pi is. Step by step tutorial including several examples of what pi is for reference.
Overview
Pi is a special number in mathematics. It is the ratio of a circle’s circumference to its diameter. No matter what size circle you use, your answer will always be pi, showing that all circles are proportional to one another. Pi is denoted by the Greek letter pi, which looks a little bit like an “n”. The numerical value of pi is 3.1415926535… but is typically shortened to the simple 3.14. Pi is very important in math and is used in all equations dealing with circles.
Tags: 3.14, arithmetic, circle, circumference, denoted, diameter, equations, Greek, letter, pi, propertional, radius, ration, size, value
Posted in Arithmetic | No Comments »
Friday, October 2nd, 2009
Identifying Subtended Angles
Description
A detailed tutorial on identifyinf subtended angles. Step by step tutorial including several examples of how to identify subtended angles for reference.
Overview
A subtended angle normally refers to an angle that is subtended by an arc. This means that the rays that make up the angle pass through the endpoints of the arc. It could also mean that an angle’s vertex point is point on the circumference of a circle. The definition typically varies a little, depending on context. Another form of a subtended angle is when a solid object subtends a solid angle.
Tags: angles, arc, circle, circumference, endpoint, Geometry, Math, ray, solid, subtended, subtends, vertex
Posted in Geometry | No Comments »
Thursday, September 17th, 2009
The perimeter of a circle is more commonly known as the circumference of a circle. The circumference of a circle is the length around it, and can be calculated from its diameter using the formula:
Or, substituting the radius for the diameter:
Where r is the radius and d is the diameter of the circle, and π (the Greek letter pi) is defined as the ratio of the circumference of the circle to its diameter (the numerical value of pi is 3.141 592 653 589 793…).
Tags: circle, circumference, circumference of circle, Geometry, Math, perimeter, perimeter of circle
Posted in Geometry | No Comments »
Monday, September 14th, 2009
Finding a the Circumference of a Circle
Description
A detailed tutorial about the circumference of a circle. Step by step tutorial including several examples of how to determine the circumference of a circle.
Overview
The circumference of a circle is the distance around the outside of the circle. The formula looks like this:
Instead of using the diamater, the radius can be used as such:
Tags: algebra, circle, circumference, Geometry, Math
Posted in Algebra, Geometry, Math | No Comments »
Tuesday, September 8th, 2009
How to Find the Perimeter
Description
This video shows the formula for finding the perimeter of a rectangle. The video gives a clear explanation of how to find the perimeter. Two example problems are provided in the video.
Overview
The perimeter of a shape is really just the outline of the shape. It can be found by adding up the lengths of all the sides of a shape – so for a rectangle, you would add two values for the length and two values for the width. For a triangle you would add together the width for each of the three sides. This can be done for every shape, except for a circle. The perimeter of a circle is called the circumference, and it has its own formula.
Tags: circumference, Geometry, Math, outline, perimeter, rectangle, square, triangle
Posted in Geometry | No Comments »
Thursday, September 3rd, 2009
Parts and Equations of Circles
Description
This video explains all the different parts of the circle, with multiple picture examples. Everything is laid out in an easy to read format and the illustrations clearly show where on the circle each part is located.
Overview
Circles are very interesting shapes in the world of geometry. There are many different parts to a circle, and many different formulas. The most common formulas are the area and the circumference formula.
Area Formula: Area = pi * radius * radius = pi * radius^2
Circumference Formula: Circumference = pi * diameter = pi * 2 * radius
The area is the area inside a circle, and the circumference is the measurement of the outside of the circle. The diameter is the width of the circle, and the radius is half of the diameter. Pi is a number that is equal to approximately 3.14.
The other parts of a circle are the sector, chord, arc, tangent, and secant. These are lines that will not show up all the time and will not always need to be acknowledged, but they do exist on the circle.
Tags: arc, area, chord, circle, circumference, diameter, Geometry, Math, pi, radius, secant, sector, tangent
Posted in Geometry | No Comments »
