Geometry Vocabulary AIR Prep Line The shortest distance

Geometry Vocabulary AIR Prep

Line The shortest distance between two points. l It is straight. It goes on forever (has arrows to show this). Trivia: a line can also be thought of an infinite amount of points touching each other.

Line Segment Part of a line. A B F C E D Does not go on forever like a line. Usually ends at points. Trivia: In theory, lines go on forever. Most of what we use in real life are line segments.

Angle The measured space or distance between two intersecting lines/segments/rays. The amount of turning between two lines meeting at a common point. Measured in degrees.

Congruent Having the same size and shape. Equal, but used for shapes rather than numbers.

Similar Having the same shape, but not necessarily the same size. Proportional.

Parallel Two lines in the same plane that never intersect. Having the same slope.

Perpendicular Two lines or line segments intersecting at exactly 90°. Having slopes that are opposite reciprocals.

Supplementary Angles or Linear Pair Two or more angles which make a line, which is 180°. Supplementary just have to add to 180°, linear must physically make a line. Supplementary, straight line.

Complementary Angles Two or more angles whose sum is 90°. Complementary, corner.

Vertical Angles Opposite angles are congruent when two lines cross.

Alternate Interior Angles On the inside of parallel lines, but on opposite sides of the transversal. Congruent only if the lines are parallel. If the angles are congruent, then the lines are parallel.

Corresponding In a different area or shape, but otherwise in the same location.

Bisect, Midpoint To cut exactly in half. Creates two congruent pieces. Also called bisector.

What is the distance formula?

Distance Formula x 1 y 1 x 2 y 2 (1, -3) (4, 8) How to find the length, or distance, between two points. A point is (x, y). 1. Label points 2. Plug into formula 3. Simplify/solve

What is the slope formula?

Slope Formula x 1 y 1 x 2 y 2 (1, -3) (4, 8) The measured slant of a line. A point is (x, y). 1. Label points 2. Plug into formula 3. Simplify/solve

Reflexive Property Something is congruent to itself. A B D C

Transitive Property/Substitution If a = b and b = c then a = c. Almost like substitution.

SSS congruence All three sides of one triangle are congruent to all three sides of another. Two triangles are congruent if all corresponding sides are congruent.

SAS Congruence Two sides on one triangle are congruent to two sides on another triangle, plus the angle between the sides are congruent on both triangles. Two triangles are congruent two corresponding sides are congruent and the included angle is congruent.

ASA Congruence Two angles on one triangle are congruent to two angles on another triangle, plus the side between the angles are congruent on both triangles. Two triangles are congruent two corresponding angles are congruent and the included side is congruent.

AAS Congruence (SAA) Two angles on one triangle are congruent to two angles on another triangle, plus the side after or before the angles are congruent on both triangles. Two triangles are congruent two corresponding angles are congruent and the side before or after the angles is congruent.

HL Congruence The hypotenuse of two triangles are congruent plus one pair of corresponding sides. Two right triangles are congruent if their hypotenuses are congruent and if one corresponding set of sides is congruent.

Hypotenuse

Opposite

Adjacent

Vertex

Edge