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Geometry
Vocabulary
Geometry Vocab 1 | Definitions |
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line segment | consists of two endpoints and all the points that lie on a line between those two endpoints |
ray | consists of an initial point and all the points on a line to one side of that point; a half line |
opposite rays | two rays that share the same initial point and form a straight line |
collinear points | points that are on the same line |
angle | consists of two different rays that have the same initial point |
acute angle | an angle with a measure greater than 0 degrees and less than 90 degrees |
right angle | an angle with a measure of 90 degrees |
obtuse angle | an angle with a measure greater than 90 degrees and less than 180 degrees |
straight angle | an angle that measures 180 degrees |
adjacent angles | two angles that share a common vertex and side, but have no common interior points |
congruent segments | segments that have the same length |
congruent angles | angles that have the same measure |
midpoint of a segment | the point that divides the segment into two congruent segments |
segment bisector | a segment, ray, line, or plane that intersects a segment at its midpoint |
angle bisector | a ray that divides the angle into two congruent angles |
perpendicular lines | two lines that intersect to form a right angle |
conditional statement | a statement made up of two parts, the hypothesis (if p) and the conclusion (then q) |
converse of a conditional statement | formed by interchanging the hypothesis and the conclusion |
counterexample | an example of a conditional statement in which the hypothesis is fulfilled and the conclusion is not fulfilled proving the statement to be false |
biconditional statement | p if and only if q; equivalent to writing p implies q and q implies p |
vertical angles | angles whose sides form two pairs of opposite rays |
linear pair | two adjacent angles whose noncommon sides form opposite rays |
complementary angles | two angles whose sum equals 90 degrees |
supplementary angles | two angles whose sum equals 180 degrees |
parallel lines | coplanar lines that do not intersect |
intersecting lines | coplanar lines that have exactly one point in common |
oblique lines | intersecting lines that are not perpendicular |
coincident lines | the same line |
contrapositive of p implies q | not q implies not p; true if and only if p implies q is true |
Law of Syllogism | p implies q, q implies r, therefore p implies r |
Law of Detatchment | p implies q, p is true, therefore q is true |
transversal | a line that intersects two or more coplanar lines at different points |
corresponding angles | angles that occupy corresponding positions when a transversal intersects two lines |
alternate interior angles | two angles that lie between two lines intersected by a transversal and on opposite sides of the transversal |
consecutive interior angles | two angles that lie between two lines intersected by a transversal on the same side of the transversal |
skew lines | lines that do not lie in the same plane |
vector | a quantity that has both quantity and magnitude |
parallel vectors | vectors that have the same or opposite direction |
congruent triangles | triangles whose corresponding angles and sides are congruent |
equilateral triangle | a triangle with three congruent sides |
isosceles triangle | a triangle with at least two congruent sides |
scalene triangle | a triangle with no congruent sides |
acute triangle | a triangle with three acute angles |
rignt triangle | a triangle with one right angle |
obtuse triangle | a triangle with exactly on obtuse angle |
equiangular triangle | a triangle with three congruent angles |
legs | the sides of a right triangel that form the right angle; the two congruent sides in an isosceles triangle |
hypotenuse | the side opposite the right angle in a right triangle |
base | the noncongruent side in an isosceles triangle |
interior angles of a triangle | the angles inside the triangle |
exterior angles of a triangle | the angles adjacent to the interior angles |