Java Games: Flashcards, matching, concentration, and word search.

Geometry Theorems and Definitions

Theorems and definitions that we need to know for the geometry exam.

AB
A theorem you prove before the main theorem to make proving the main theorem easier is called a ?lemma
If a line is perpendicular to a plane, then it is perpendicular to every ? that passes through the ?line / point of intersection (foot)
The point of intersection of a line and a plane is called the ?foot
A line is perpendicular to a plane if and only if it is perpendicular to ? that passes through the footevery line
If B and C are each equidistant from P and Q, then every point between B and C is ? from P and Qequidistant
State the Basic Theorem on PerpendicularityIf a line is perpendicular to each of 2 intersecting lines at their point of intersection, then it is perpendicular to the plane that contains them
If 2 sides of a triangle are of unequal length, then the angles opposite them are of ? and the ? angle is opposite the longer sideunequal measure / larger
State the Parts TheoremIF D is a point on segment AB between A and B, then segment AB is greater than segment AD and segment AB is greater than segment DB. If D is a point on the interior of angle ABC, than the measure of angle ABC is greater than the measure of angle ABD and the measure of angle ABC is greater than the measure of angle DBC.
State the Exterior Angle TheoremThe measure of an exterior angle is greater than the measure of both its remote interior angles.
If one angle of a triangle is a right angle, then the other 2 angles must be ?acute
The sum of the measures of any 2 angles of a triangle must be less than ?180
State the Hypotenuse Leg TheoremIf the hypotenuse and leg of one right triangle are congruent to the corresponding parts of a 2nd triangle, then the triangles are congruent
State the Hypotenuse Acute Angle TheoremIf the hypotenuse and an acute angle of one right triangle are congruent to the corresponding parts of a 2nd triangle, then the triangles are congruent
State the Leg Acute Angle TheoremIf a leg and an acute angle of one right triangle are congruent to the corresponding parts of a 2nd triangle, then the triangles are congruent
State the Leg Leg TheoremIf 2 legs of one right triangle are congruent to the corresponding parts of a 2nd triangle, then the triangles are congruent
State the Contrapositive of ITTIf 2 angles of a triangle are not congruent, then the sides opposite those angles are not congruent and the longer side is opposite the larger angle
State the Inverse of ITTIf 2 sides of a triangle are not congruent, then the angles opposite those sides are not congruent and the larger angle is opposite the longer side
State the 1st Minimum TheoremThe shortest segment from a point to a line is the perpendicular segment
State the Triangle Inequality TheoremThe sum of the lengths of any 2 sides of a triangle must be greater than the length of the 3rd side
State the Hinge TheoremIf 2 sides of 1 triangle are congruent to the corresponding parts of a 2nd triangle and the included angle of tehe 1st triangle is greater than the included angle of the second triangle, then the 3rd side of the 1st triangle is greater than the 3rd side of tehe 2nd triangle
State the Converse of the Hinge TheoremIf 2 sides of 1 triangle are congruent to the corresponding parts of a 2nd triangle and the 3rd side of the 1st triangle is greater than the 3rd side of the 2nd triangle, then the included angle of the 1st triangle is greater than the included angle of the 2nd triangle
The perpendicular segment from a vertex of the triangle to the line containing the opposite side is the ?altitude
The median, angle bisector, and altitude of a triangle are distinct segments except in an isosceles triangle when they are ?the same segment
The length of the altitude of any angle of a triangle is ? the lengths of at least 2 sides of the triangleless than or equal to
The altitudes to the congruent sides of an isosceles triangle are ?congruent
If 2 altitudes of a triangle are congruent, then the triangle is ?isosceles
The altitude to the base of an isosceles triangle is also a ?median
The altitudes of a(n) ? triangle are congruentequilateral
The perimeter of a triangle is ? than the sum of the 3 altitudesgreater than
Given an altitude, an angle bisector, and a median, the altitude is the ? and the median is the ? of these 3 segmentsshortest / longest
A theorem that states whether or not 2 sets intersect and if they intersect what the intersection looks like is called a ? theoremincidence
This type of theorem shows at least 1existence
This type of theorem shows at most 1uniqueness
This type of theorem shows exactly 1existence and uniqueness
A theorem that states a condition that is satisfied by every point in a set, but none outside of the set is called a ? theoremcharacterization
A line perpendicular to a segment at its midpoint is called a ?perpendicular bisector
In a given plane, through a given point of a given line, there is ? line perpendicular to the given lineexactly 1
State the Perpendicular Bisector TheoremIn a plane, the perpendicular bisector of a segment is the set of all points in the plane equidistant from the endpoints of the segment
In a plane, if 2 points of a line are each equidistant from the endpoints of a segment, then the line is the ? of the segmentperpendicular bisector
Through a given external point there is ? line perpendicular to a given lineexactly 1
No triangle has more than one ?right angle
The longest side (side opposite the right angle) of a right triangle is the ?hypotenuse
A set of points used to make a proof easier is called a(n) ?auxiliary set
If A-M-B on line L, then A and M are on the ? of any other line that contains Bsame side
If A-M-B on line L and C is a point not on L then M is in the ? of angle ACBinterior
State the Crossbar TheoremIf M is in the interior of angle ACB then ray CM intersects segment AB
If A-M-C on line L then A and C are on ? of any other line that contains Mopposite sides
State the GH1 postulateIf A and E are on the same side of line BD and H and E are on the same side of line BD then A and H are on the same side of line BD
"If P then Q" is the ?conditional
"If Q then P" is the ?converse
"If not P then not Q" is the ?inverse
"If not Q then not P" is the ?contrapositive
Conditional and Contrapositive always have the same ?truth value
Converse and Inverse always have the same ?truth value
A statement that uses the words "if and only if" is a ? statementbiconditional
An isosceles triangle has ? sides congruentat least 2
An equilateral triangle has ? sides congruent3
A scalene triangle has ? congruent sides0
An equiangular triangle has ? congruent angles3
A theorem that is the immediate consequence of another theorem is a ?corrollary
State the Isosceles Triangle TheoremIf 2 sides of a triangle are congruent,then the angles opposite them are congruent
State the Converse of the Isosceles Triangle TheoremIf 2 angle of a triangle are congruent, then the sides opposite those angles are congruent
The bisector of the angle opposite the base of an isosceles triangle ? the base and is ? the basebisects / perpendicular to
A line segment whose endpoints are a vertex of the triangle and the midpoint of the opposite side is called a ?median
the point of concurrency for medians is called the ?centroid
the centroid is ? the way from the vertex to the opposite side2/3
A line segment that lies on the bisector of the angle and has its endpoints as a vertex of the triangle and some point on the opposite side is called the ?angle bisector of a triangle
the point of concurrency for angle bisectors is called the ?incenter
a closed 4 sided figure is called a ?quadrilateral
A quadrilateral with 4 right angles is called a ?rectangle
a rectangle with 4 congruent sides is called a ?square
the segment that joins 2 non-consecutive vertices of a quadrilateral is called the ?diagonal
the median to the base of an isosceles triangle is ? the base and ? the angle opposite the baseperpendicular to / bisects
the medians to the congruent sides of an isosceles triangle are ?congruent
Given 2 congruent triangles, the median to a side of 1 triangle is ? to the median to the corresponding side of the other trianglecongruent
the median to the base of an isosceles triangle ? the vertex anglebisects
If a segment is perpendicular to one side of a triangle and also bisects the angle opposite that side, then the triangle is ?isosceles
the point of concurrency for altitudes is called the ?orthocenter

This activity was created by a Quia Web subscriber.
Learn more about Quia
Create your own activities