Chapter 10 Flashcards Preview

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Flashcards in Chapter 10 Deck (50):
1

Center

part of a circle that all points are equidistant from

2

Central Angle

angle with vertex in center of circle

3

chord

segment with endpoints on the circle

4

circle

set of all points equidistant from a given point

5

circumference

distance around the circle

6

diameter

chord that passes through center and is made of collinear radii

7

pi

the ration c/d, as an irrational number

8

radius

segment with endpoints at center and on the circle

9

Circle pairs

1. 2 circles are congruent if they have congruent radii
2. all circles are similar

10

Concentric Circles

coplanar circles with same center

11

Inscribed polygon

polygon with vertices on the circle

12

Circumscribed polygon

polygon outside the circle

13

Arc

portion of the circle defined by 2 endpoints

14

Central Angle

angle with vertex in the center of the circle

15

Sum of Central Angles

360 degrees

16

Minor arc

connecting two endpoint that make up less than 180*

17

Major arc

connecting two endpoint s that make up more than 180*

18

Semicircle

arc with endpoints that lie on a diameter, or 180*

19

Congruent Arcs

arcs in same or congruent circles that have the same measure

20

In the same circle or in congruent circles, two minor arcs are congruent if an only if....

their central angles are congruent

21

Adjacent arc

arcs in a circle with exactly one point I common

22

Measure of arc formed by 2 adjacent arcs is the sum of the measure of

the two arcs

23

Arc Length

distance between endpoints along an arc, measured in degrees

24

in the same circle or congruent circles, 2 minor arcs are congruent if and only if their corresponding chords are...

congruent

25

If a diameter or radius of a circle is perpendicular to a chord, then it...

bisects the chord and its arc

26

The perpendicular bisector of a chord is...

the diameter or radius of a circle

27

In the same circle or in congruent circles, 2 chords are congruent if and only if they are _______ from the _______

equidistant, center

28

Inscribed Angle

angle with a vertex on the circle and sides that contain chords of the circle

29

Intercepted Arc

endpoints on the sides of an inscribed angle and lies on the interior of the inscribed angle

30

If an angle is inscribed in a circle, the measure of the circle is ____ of the intercepted arc

1/2

31

If two inscribed angles of a circle intercept the same arc or congruent arcs, the angles are

congruent

32

An inscribed angle of a triangle intercepts a diameter or semicircle only if the angle is a _______ angle

right

33

If a quadrilateral is inscribed in a circle, it's opposite angles are....

supplementary

34

Tangent to a Circle

a line that intersects the circle at exactly one point

35

Common Tangent

line, Ray, or segment that is tangent to 2 circles in the same plane

36

In a plane, a line is tangent to a circle if and only if it is _______ to a radius drawn to point of tangency

perpendicular

37

If two segments from the same exterior point are tangent to a circle, they are....

congruent

38

Secant

line that intersects a circle at 2 points

39

If an angle's vertex is at the center of the circle, it's measure is _____

same as the measure of the arc

40

If an angle's vertex is on the circle, it's measure is

1/2 the measure of it's arc

41

If an angle's vertex is on the interior of the circle, it's measure is.....

1/2 (sum of arc)

42

If an angle's vertex is on the exterior of the circle, it's measure is....

1/2 (difference of arcs)

43

chord segments

two chords that intersect inside a circle, each chord being divided into 2 segments

44

secant segment

segment of a secant line that has exactly one endpoint on the circle

45

If 2 chords intersect in a circle, their _______ are equal

products

46

external secant segment

secant segment that lies on the outside of the circle with one endpoint on the circle

47

If 2 secants intersect on the outside of the circle, you.....

multiply the outside (external secant segments) by the outside plus the inside (x(x+y)) and those equal each other

48

If a tangent and a secant intersect in the exterior of a circle, the _______ equals the _______

square of tangent, product of secant and ESS

49

"Completing the square" Formula

(b/2)^2

50

Equation of a Circle in Standard Form

(x-h)^2 + (y-k)^2 = r^2