Chapter 5 Flashcards
Perpendicular Bisector Theorem
If a point is on the perpendicular bisector of a segment, then it is equidistant from the endpoints of the segment.
Perpendicular Bisector
A segment Bisector that is perpendicular to the segment it bisects.
Perpendicular Bisector Converse Theorem
If a point is equidistant from the endpoints of a segment, then ur is on the perpendicular bisector.
Distance between a point and a line
Length of a perpendicular segment from the point to the line.
Angle Bisector Theorem
If a point is on the Bisector of an angle, then it is equidistant from the two sides of the angle.
Angle Bisector Converse Theorem
If a point is in the interior of an angle and is equidistant for the sides of the angle, then it lies in the Bisector of the angle.
Perpendicular Bisector of a triangle
A segment that is part of a perpendicular Bisector of one of the sides
Angle Bisector of a triangle
A segment that bisects one of the angles of the triangle.
Median
A segment whose endpoints are a vertex and the midpoint I the opposite side (A median is always a segment Bisector, sometimes a perpendicular Bisector)
Altitude
A segment from a vertex that is perpendicular to the opposite side or to the line containing the opposite side (An altitude may be inside or outside a triangle.)
Notes #1
In an isosceles triangle, the perpendicular Bisector, angle Bisector, median, and altitude are all the same segment when the segment is drawn to the base.
Notes #2
In an equilateral triangle, the perpendicular Bisector,angle Bisector, median, and altitude are all the same regardless of the sides the segment is drawn to.
Concurrent Lines
A set of lines that share a single point of intersection
Hinge Theorem
If two sides of one triangle are congruent to two sides of a second triangle, and the included angle of the first is greater than the included angle of the second, the the length of the third side of the first triangle is longer than the third side of the second triangle.
Hinge Theorem Converse
If two sides of one triangle are congruent to two sides of a second triangle, and the third side of the first triangle is congruent to the third side of the second triangle, then the included angle of the first triangle is greater than the included angle of the second triangle.
Midsegment
A segment that connects the midpoints of two sides of a triangle.
Midsegment Theorem
In any triangle, a segment joining the midpoints of any two sides will be parallel to the third side and half its length.
Triangle Inequality Theorem
Any side of a triangle is always shorter than the sum of the other two sides
Circumcenter
The point of intersection of the three perpendicular bisectors of a triangle. (Equidistant from the vertices of a triangle)
Incenter
The point of intersection of the three angle bisectors of a triangle. (Equidistant from the three sides of a triangle)
Centroid
The point of intersection of the three medians of the triangle. (2/3 of the distance from each vertex to the midpoint of the opposite side.)
Orthocenter
The point of intersection of the three altitudes of a triangle.