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Posts Tagged ‘pi’

Volumes – Cylinders

Friday, September 4th, 2009

How to Find the Volume of a Cylinder

Description

This video gives two different ways that you can find the volume of a cylinder. It provides the volume formula and several example problems.

Overview

Finding the volume of a cylinder is not hard – all you need is to find the right values. The volume of a cylinder can be expressed as:

V = pi * r^2 * h

The variable r represents the raidus of the circle found on the bottom and top of the cylinder, normally called the base. The variable h represents the height of the cylinder. Pi is a number equal to approximately 3.14.

Tags: cylinder, finding volume, Geometry, height, Math, pi, radius, volume, volume of a cylinder
Posted in Geometry | No Comments »

Degrees and Radians

Thursday, September 3rd, 2009

How to Convert Degrees into Radians

Description

This video gives an in-depth tutorial on how to convert degrees to radians, and how to convert radians back into degrees. Many examples are provided and explanations are set up in an easy to understand fashion.

Overview

Degrees are a very common thing to see – they are used in solving angles, and sometimes used in solving trangle problems. However, degrees are only a unit, and like any unit they can be converted to another one. Degrees are converted to radians – radians are used with sine, cosine, and tangent. The easiest way to remember radians is to memorize the most common degrees and their conversion into radians:

0 degrees = 0 radians

30 degrees = pi/6 radians

45 degrees = pi/4 radians

60 degrees = pi/3 radians

90 degrees = pi/2 radians

Tags: angles, cos, cosine, degrees, Math, pi, radians, sin, sine, tan, tangent, triangles, trigonometry
Posted in Trigonometry | No Comments »

Circles

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 »