Term
triangle midsegment theorem 

Definition
if a segment joins the midpoints of 2 sides of a triangle, then the segment is parallel to the 3rd side, and is 1/2 it's length. 


Term
perpendicular bisect theorem 

Definition
if a point is on the perpendicular bisector of a segment, then it is equidistant from the endpoints of the segment 


Term
converse of the perpendicular bisect theorem 

Definition
if a point is equidistant from the endpoints of a segment then it is on the perpendicular bisector of the segment. 


Term

Definition
if a point lies on the bisector of an angle, then the point is equidistant from the sides of the angle. 


Term

Definition
The perpendicular bisectors of the sides of a triangle are concurrent at a point equidistant from ther vertices 


Term

Definition
The bisectors of the sides of a triangle are congruent at a point equidistant from the sides. 


Term

Definition
a segment whose endpoints are a vertex of a traingle and a midpoint of the side opposite that vertex. 


Term

Definition
has 1 endpoint at a vertex of a triangle and the other on the line htat contains the side opposite that vetex so that the segment is perpendicular to this line. 


Term

Definition
3 angles 3 angle bisectors 3 altitudes 


Term
a segment is an angle bisector if and only if 

Definition
it lies in the ray which bisets an angle of the triangle its endpoints are the vertex of this angle and a point on the opposite side of that vertex 


Term

Definition
the intersection of the perpendicular bisectors of a triangle 


Term

Definition
3 or more lines that intersect in a single point 


Term

Definition
the intersection of the angle bisectors of a triangle it is the center of an inscribed circle. is equidistant from the sides of the triangle 


Term

Definition
the point of concurrency of the medians of a triangle. it is also called the "center of gravity. " it is 2/3 of the distance from the vertex to the midpoint of the opposite side. 

