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