Circles

Question 1

Circle

Answer 1

The set of points equidistant from a given point (the center)

Question 2

Radius

Answer 2

A segment with endpoints at the center on the circle

Question 3

Chord

Answer 3

A segment with endpoints on the circle

Question 4

Diameter

Answer 4

A chord that passes through the center (Diameter = 2 x radius)

Question 5

Secant

Answer 5

A line that intersects the circle in two places

Question 6

Tangent

Answer 6

A line that intersects the circle at exactly one place

Question 7

Point of Tangency

Answer 7

The point at which the tangent line intersects the circle

Question 8

Central Angle

Answer 8

An angle with a vertex at the center, and two sides that are radii

Question 9

Inscribed Angle

Answer 9

An angle with a vertex on the circle, and two sides that are chords

Question 10

Arc

Answer 10

A portion of the edge of the circle defined by the two endpoints
Symbol: ⌒

Question 11

Minor Arc

Answer 11

An arc with a measure less than 180 degrees
use 2 letters to name it!

Question 12

Major Arc

Answer 12

An arc with a measure greater than 180 degrees
use 3 letters to name it!

Question 13

Semicircle

Answer 13

An arc with endpoints on the diameter
Always equal to 180!

Question 14

Formula: Area

Answer 14

π r 2
(where r = radius)

Question 15

Formula: Circumference

Answer 15

C=2πr
(where r = radius)
C=πd
(where d = diameter)

Question 16

Arc Lenght

Answer 16

l= x⋅c / 360
(where c = circumference and x = degree of arc