Circles YAY!

Today we learned about circles. And just pointing out that i was the last to post both Trimesters so ha.

A Circle is the set of all points in a plane that are a given distance form a given point in the plane.  The given point is the center of the circle, and the given distance is the radius.

A chord is a segment joining any two points of a circle.  The diameter is the longest chord, and is twice the radius.  A secant line goes through two points on the circle.  A tangent lines intercepts a circle at exactly one point(the point of tangency)  

This is an externally tangent circle.                            These circles
                                                                              are internally tangent.

These are concentric circles. 











There were many theorems that we learned, they were...
-If a radius is perpendicular to a chord, then it bisects the chord.
-If a radius of a circle bisects a chord that is not a diameter, then it is perpendicular to that chord.

-The perpendicular bisector of a chord passes through the center of the circle.   

We also found that you can find the center of a circle, when you aren't given a complete circle by drawing chords.  And then using those silly compasses. 




In 10.2 we learned about congruent chords.  We learned two theorems.
-If two chords of a circle are equidistant from the center, then they are congruent.
-If two chords of a circle are congruent, then they are equidistant form the center of the circle. 

If AB≅ CD then GM≅EM
If GM≅EM then AB≅CD










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I bet you just all lost didn't you?


Happy blogging
-Jennifer Kendall.