Chapter 10 Flashcards
circle
A set of all points that are equal distance from the center point
radius
The distance from the center to a point on the circle
all radii within a circle must be
congruent
Two different circles I have the same length radii are
Congruent
Two different circles with different length radii are
similar
diameter
hey, segment through the center which also connect to point on the circle
radius equals
1/2 diameter
diameter equals
Two times radius
chord
any segment, which connects two points of a circle
concentric circles
Coplanar circles that have a common center
tangent
A line in the same plane as a circle that intersects a circle at exactly 1 point
point of tangency
The point at which the tangent intersects with the circle
common tangent
A line that is tangent of two coplanar circles at the same time
if a line is tangent to a circle…
then it is perpendicular to the radius, drawn, from the point of tangency
tangent and radius are
perpendicular
if two segments from the same exterior point, or tangent to a circle
then the two segments are congruent AKA ice cream cone theorem
central angle
An angle, whose vertex is the center of a circle
arc
Part of a circle
intercepted arc
The part of the circle that is inside of the angle
circles are measured in
degrees
arcs are measured in
degrees
semi circle
If the endpoints of an arc, or the endpoints of a diameter than the arc is a semi circle
minor arc
Less than half of a circle (greater than 0, less than 180)
major arc
more than half of a circle (greater than 180 and less than 360)
minor arcs are name by how many letters
2
Major arcs your name by how many letters
3
The measure of a central angle is the ______ as the measure of its intercepted arc
same
How to find the measure of a major are given a minor arc
360-minor arc
two arcs are _______ if they share a common endpoint
Adjacent
lil arc + little arc
= big arc
arcs are congruent if they have…
The same measure in the same circle or in different circles
If two chords are congruent
Then their corresponding arcs are congruent
If the diameter of a circle is perpendicular to a cord
then the diameter by six the cord and it’s arc
If 2 quarts are equal distance from the center
Then the two cords are congruent
inscribed angle
An angle whose vertex is on the circle, and who sides contain chords of the circle
The measure of an inscribed angle is
Half of it intercepted arc
If two or more inscribed angles of a circle intercept the same arc
Then the inscribed angles are congruent
if all the vertices of a polygon lie on a circle then we say that the polygon is _______ in the circle
Inscribed
If an inscribed angle of a triangle intercepts the semi circle, and therefore the diameter
Then the inscribed angle is a right angle
if a quadrilateral is inscribed in a circle
Then it’s opposite angles are supplementary
Dead giveaway for (diameter is perpendicular to the cord bisects the cord and arc)
one 90 angle
Dead giveaway for (two cords, congruent if they are equidistant from the center)
two 90 angles
