Class Summary 090304

Today we started our class by checking the homework we had, which was page 479 #17-40 all exept 37.

The only exercise we went over were # 39.

I think alot of people forgot how to find the slope.. but you'll have to use the slope-fromula

you do that, and then your final answer should be

After that we saw one thing that we didn't see yesterday, we saw the inscribed angles the other day, and that is a triangle whos vertexes are Inside the Circle. Today we saw a new thing; Circumscribed Polygons.

that is a polygon with the sides Outside the circle, but the sides are intersecting the circle at Exactly ONE point, in other words a tangent.

And then we went on for today's class!

SECANT

Definition: A Line passing through the circle and intersecting it Twice.

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Then we went over 3 theorems.

Theorem 9-11:

if: a tangent and a secant intercept at the point of tangency,

then: each angle formed is 1/2 of the corresponding arc.

Theorem 9-12:

in this one there is a formula that will make it easier to understand.

So if: 2 secants meet INSIDE a Circle then you can apply this.

Theorem 9-13:

( make sure that you have the biggest arc firts, and then u subtract the small one, otherwise you would get a negative answer and an angle cannot have a negative measurement)

to find angle T.

arc BC - arc AD divided by 2