3-4 Radian Measures

So far, we have learned about degree measures on a unit circle. Now, we get to learn about radian measures!

Here's the basic info:

The concept of a radian:
π=circumfrance/diameter
In half of a circle, there are π number of radians.

Each of the curved lines represent one raidan in the unit circle.

In terms of a circle, a radian can be seen as the ratio of the length of the arc subtended by two radii to the radius of the circle.

Half of the circumfrance is π, so at 180°, the radian measure at 180 is π.

Converting radians to degrees and degrees to radians:

To convert degrees to radians, you multipy the angle measure in degrees and multiply it by π/180.

For example:

36°= 36 * π/180= 36π/180=π/5

and

To convert radians to degrees, you multiply the radian measure and multiply it by 180/π.

For example:

π/6 Radians:

π/6 * 180/π=180/6=30°

Special Angles:

Here are the special angles we get to learn about.

0° = 0 radians

30°=π/6 radians

45°= π/4 radians

60°=π/3 radians

90°=π/2 radians

180°=π radians

Other helpful stuff:

You can switch between degrees and raidans on your calculator by going to mode, and then choosing between radians and degrees.

In the angle menu:

You can give radians and it will give you degrees in radian mode if you choose the degree symbol.

You can also give degrees and get radians in the degree mode if you choose the rad option.

That's pretty much it!

Here's a good site to look if you need more info:http://www.themathpage.com/aTrig/radian-measure.htm

A Reminder to P Dubs....a.k.a. Paul to do the next posting!

Now for my personalization (which must be done in green)!

First, I have to say, the Prep Varsity Tennis Team beat Poly again today! Woo hoo! This is very exciting news and I expect many congrats from you all tomorrow...jk.

Also...here is a link for a really yummy recipe because cooking is fun and you should all do it too! They are spooky spice cookies just in time for Halloween!http://www.foodnetwork.com/food/recipes/recipe/0,,FOOD_9936_34566,00.html