Acute VOCABULARY Chapters 1, 2, 3, 4, 5, 9, and 8 WORD IMAGE DEFINITION Acute angle An angle with measure between 0 and 90 56 60 70 50 A with three acute. Adjacent Alternate interior Altitude of a Angle Angle of Depression 1 2 Two in a plane that have a common vertex and a common side but no common interior points. 1 and 2 are adjacent Two nonadjacent interior on opposite sides of the transversal. *When 2 parallel lines are cut by a transversal, alternate interior are congruent. The perpendicular segment from a vertex to the line containing the opposite side. A figure formed by two rays that have the same endpoint. Angle of Elevation Biconditional Statement A statement that contains the words if and only if. Angle bisector A ray that divides the angle into two congruent adjacent. If BD bisects ABC, then 1 2. Centroid medians of a. It is known as the center of gravity.
Circumcenter perpendicular bisectors of a. It is the center of the circumscribed circle around a. Collinear points Points all in one line. Complementary 30 60 Two whose measures have a sum of 90. Conclusion A statement whose basic form is If p, then q. q is the conclusion. Conditional Statement A statement in the form if then. The basic form of a conditional statement is If p, then q. Congruent Angles with equal measurement Congruent polygons Figures that have the same size and shape. Congruent segments Segments that have equal lengths. Converse The statement formed by switching the hypothesis and conclusion of a conditional statement: If q, then p. Coplanar points Points all in one plane. Corresponding Two in corresponding positions relative to two lines. *When 2 parallel lines are cut by a transversal, corresponding are congruent. Cosine Counterexample Ex. If an animal is a bird, then it can fly. Counterexample: A penguin is a bird, but An example used to prove that an if-then statement is false.
Deductive reasoning Dilation Equiangular cannot fly. Therefore, a penguin is a counterexample. Solving a proof is an example of using deductive reasoning. Proving statements by reasoning from accepted postulates, definitions, theorems, and given information. A transformation that preserves angle measure and results in an image with lengths proportional to the pre-image lengths. Example: Changing a smaller image into a bigger image. A with all congruent. Equidistant The same distance from two or more objects. Equilateral A with three congruent sides. Exterior angle of a ExteriorAngle The angle formed when one side of the is extended. Hypotenuse The longest side of a right located across from the right angle. Hypothesis Image A statement whose basic form is If p, then q. Statement p is the hypothesis. Each point P in a given set is mapped to exactly one point P in the same or a different set. P is called the image of P. Incenter angle bisectors of a. Inductive reasoning Isosceles A pop quiz is given the first three Fridays of the school year, so you conclude their will be a pop quiz every Friday. A kind of reasoning in which the conclusion is based on several past observations. A with at least two sides congruent.
Legs of an isosceles Legs of a right The two congruent sides. The two sides that create the right angle. Length of a segment The distance between its endpoints. Line Linear Pair A geometric figure which extends in two directions without ending. It has infinite points and no thickness. A pair of adjacent whose noncommon sides are opposite rays. Median of a A segment from a vertex to the midpoint of the opposite side in a. Midsegment of a The segment that joins the midpoint of two sides of a. Midpoint Non-collinear points The point that divides a segment into two congruent segments. Points not all in one line. Non-coplanar points Points not all in one plane. Obtuse angle An angle with measure between 90 and 180. Obtuse A with one obtuse angle. Opposite rays Rays that have the same endpoint and go in opposite directions. Orthocenter altitudes of a.
Parallel lines Coplanar lines that do not intersect. Parallel planes Planes that do not intersect. Perpendicular bisector of a segment A line, segment, ray, or plane that is perpendicular to the segment at its midpoint. Perpendicular lines Two lines that intersect to form right or 90. Plane Point Points of Concurrency NOT DEFINED, only described: Extends without ending and has no thickness and no edges. We usually picture a plane by drawing a four-sided figure. NOT DEFINED, only described: A dot that doesn t have size, but does have some size. A point where three or more lines coincide. Polygon Postulate EX. Angle Addition Postulate : Little Angle + Little Angle = Big Angle Pythagorean Theorem A closed plane figure formed by three or more segments such that each segment interacts exactly two other segments only at their endpoints and no two segments with a common endpoint are collinear. A statement that is accepted without proof. In a right, the sum of the squares of the legs is equal to the sum of the square of the hypotenuse. Quadrilateral A four sided polygon. Ray Starts at an endpoint and goes in any direction without ending.
Reflection A transformation in which a line of reflection acts like a mirror, reflecting points to their images. Remote Interior Angles An interior angle of a polygon that is not adjacent to the exterior angle. Right angle An angle with measure of 90. Right A with one right angle. Rotation A transformation that turns a figure about a fixed point a number of degrees. Same-side interior Two interior on the same side of the transversal. *When 2 parallel lines are cut by a transversal, same side interior are supplementary. Scalene A with no congruent sides. Segment of a line Segment bisector Two points on the line and all points between them. A line, segment, ray, or plane that intersects a segment at its midpoint. Sine Skew Lines Lines that are not coplanar and do not intersect.
Straight angle An angle measure of 180. Supplementary Two whose measures have the sum of 180. Tangent Theorem Transformation EX. Vertical Angle Theorem: Vertical Angles are congruent. A statement that has been proven. A change in position, size, or shape of a figure. Translation A transformation that moves every point in the figure the same distance in the same direction. Transversal A line that intersects two or more coplanar lines in different points. Triangle Vertex of an angle A figure formed by three segments joining three noncollinear points. The common endpoint in an angle. Vertex of a Each of the three points of the. 120 Vertical The nonadjacent formed by two intersecting lines.