Ch9 Flashcards
Circle
A circle is the locus of a moving point p in a plane which is always equidistant from some point o
Circumference
The length of boundary of a circle
2πr
Arc
A part of the circumference
Chord
Straight line joining any two points of the circumference
Segment
The portion of a circle bounded by an arc and a chord
Sector
A part of circle bounded by two radii and an arc intercepted between them
Minor arc major arc
An arc which is included in a semi circle
An arc which includes semi circle
Radius
The distance of any point of the circle to its centre
Radial segment
Line segment joining any point of the circle to the centre
Diameter
A chord passing through the centre of the circle
Interior exterior
Set of all points lying inside the boundary of circle
A set of all points lying outside the boundary of circle
Central angle
The angle subtended by an arc at the centre of the circle
Circumangle
The angle subtended by an arc at the circumference of the circle
Cyclic
A quadrilateral is called cyclic if a circle can be drawn through it’s four vertices
Projection
The projection of the given point on a line segment is the foot of perpendicular drawn from the point on that line segment
Projection of vertical line segment
Cd on a line segment ab is a point on ab which is of zero dimension
Secant line
Is a straight line which cuts the circumference of a circle in two distinct points
Tangent line
Straight line which touches the circumference at a single point only point of tangency is also known as point of contact
Projection of line segment
Cd on a line segment ab is portion ef of the latter intercepted between foots of the perpendiculars drawn from c and d
