Chapter 5 Flashcards
(27 cards)
Coordinate Proof
When proving the triangle Midsegment Theorem use coordinate geometry and algebra
Triangle Midsegment Theorem
if a segment joins the midpoints of two sides of a triangle, then the segment is parallel to the third side and half its length
Theorem 5-2 Perpendicular Bisector Theorem
If a point is on the perpendicular bisector of s segment, then it is equidistant from the endpoints of a segment
Theorem 5-3 Converse of Perpendicular Bisector Theorem
If a point is equidistant from the endpoints of a segment, then it is in the perpendicular bisector of the segment
Theorem 5-4 Angle Bisector Theorem
If a point is on the bisector of an angle, then the point is equidistant from the sides of the angle
Theorem 5-5 Converse of Angle Bisector Theorem
If a point the interior of an angle is equidistant from the sides of the angle, then the point is on the angle bisector
Distant from a point to a line
The distance from a point to a line is the length o the perpendicular segment from the point to a line
Theorem 5-6
The perpendicular bisectors of the sides of a triangle are concurrent at a point equidistant from the vertices
Theorem 5-7
The bisectors of the angles of a triangle are concurrent at a point equidistant from the sides
Concurrent
When three or more lines intersect in one point
Point of concurreny
The point at with they intersect is the point of concurrency
Circumcenter of the triangle
The point at which they intersect is the circumcenter of the triangle
Theorem 5-8
The medians of the triangle are concurrent at a point that is two thirds the distance from each vertex to the midpoint of the
opposite side
Centroid
The point of concurrency of medians is the centroid
Median of a triangle
A median of a triangle is a segments whose endpoints are a vertex and the midpoint of the opposite side
Altitude
An altitude of a triangle is the perpendicular segment from a vertex to the line containing the opposite side
Negation
The negation of a statement has the opposite truth value
Inverse
The inverse of a conditional statement negates both the hypothesis and the conclusion
Contrapositive
The contrapositive of a conditional switches both the hypothesis and the conclusion and negates both
Equivalent statements
Statements that have the same truth value
Indirect reasoning
All possibilities are considered until all but one are proved false. The remaining possibility must be true
Indirect proof
A proof involving indirect reasoning is called an indirect proof. In such a proof, a statement and its negation often are the only possibilities
Comparison property of inequality
If a=b+c and c>0, then a>b
Corollary to the triangle angle sum theorem
The measure of an exterior angle of a triangle is greater than the measure of each of its remote interior angles