Geometry Vocab

an angle that measures greater than 0 degrees and less than 90 degrees

for two lines intersected by a transversal, a pair of angles that lie on opposite sides of the transversal and outside the other two lines

for two lines intersected by a transversal, a pair of nonadjacent angles that lie on opposite sides of the transversal and between the other two lines

two rays that meet at a point

a ray that divides an angle into two congruent angles

a combination of two conditional statements

points that lie on the same line

two angles whose measures have a sum of 90 degrees

a statement that can be written in the form "if p, then q" where p is the hypothesis and q is the conclusion

having the same size and shape

a statement that is believed to be true

the hypothesis and the conclusion in a conditional statement are opposed, and then swapping the order

the statement formed by exchanging the hypothesis and conclusion of a conditional statement

points that lie in the same plane

an example that proves that a conjecture or statement is false

the process of using logic to draw conclusions

a shape that results from a transformation of a figure known as the preimage

the process of reasoning that a rule or statement is true because specific cases are true

a transformation that does not change the size or shape of a figure

one of the two sides of the right triangle that form the right angle

an undefined term in geometry, a line is a straight path that has no thickness and extends forever

a line that divides a plane figure into two congruent reflected halves

a part of a line consisting of two endpoints and all points between them

a figure that can be reflected across a line so that the image coincides with the preimage

a pair of adjacent angles whose noncommon sides are opposite rays

the point that divides a segment into two congruent segments

points that do not lie on the same line

an angle between 90 and 180 degrees

two rays that have a common endpoint and form a line

lines that never intersect or touch

a line perpendicular to a segment at the segment's midpoint

lines that intersect at 90 degrees

an undefined term in geometry, it is a flat surface that has no thickness and extends forever.

an undefined term in geometry, it names a location and has no size

a statement that is accepted as true without proof

the original figure in a transformation

a part of a line that starts at an endpoint and extends forever in one direction

a transformation across a line, called the line of reflection, such that the line of reflection is the perpendicular bisector of each segment joining each point and its image

an angle that measures 90 degreees

a transformation about a point, also known as the center of rotation, such that each point and its image are the same distance from it. all of the angles with the same vertex are congruent

a figure that can be rotated about a point by an angle less that 360 degrees so that the image coincides with the preimage has rotational symmetry

for two lines intersected by a transversal, a pair of angles that lie on the same side of the transversal and between the two lines

a line, ray, or segment that divides a segment into two congruent segments

an angle of 180 degrees

two angles whose measures have a sum of 180 degrees

in the transformation of a figure such that the image coincides with the preimage, the image and preimage have symmetry

a statement that has been proven

a change in the position, size, or shape of a figure or graph

a transformation that shifts or slides every point of a figure or graph the same distance in the same direction

a line that intersects two coplanar lines at two different points

a basic figure that is not defined in terms of other figures. the undefined terms in geometry are point, line, and plane

a quantity that has both magnitude and direction

the point of intersection of two rays

the nonadjacent angles formed by two intersecting lines