Unit 5 Vocab

By: Mika Hamady

Acute Angle

Definition: An acute angle is an angle that is less then 90 degrees.

Examples:1. A 43 degree angle is acute2. A 89 degree angle is acute

Adjacent Angles

Definition: Adjacent angles are angles that have a common ray coming out of the vertex going between two other rays. In other words, they are angles that are side by side, or adjacent.Examples:

Axis

Definition: The vertical and horizontal lines that make up the quadrants of a coordinate plane. The vertical axis is usally referred to as the y axis and the horizontal axis is usually referred to as the x axis.Examples:

Bisecting an Angle

Definition: Dividing an angle into two equal parts.

Examples:

Concentric Circles

Definition: Concentric objects share the same center, axis or origin with one inside the other. Circles, tubes, cylindrical shafts, disks, and spheres may be concentric to one another. Concentric objects generally have different radii, as concentric objects with the same radius are equal.Examples:

Congruent Figures

Definition: Two objects are congruent if they have the same dimensions and shape. Very loosely, you can think of it as meaning 'equal', but it has a very precise meaning that you should understand completely, especially for complex shapes such as polygons.Examples:

Consecutive Angles

Definition: Angles that occur one right after the other. Consecutive angles are on either end of the same line segment in a polygon.

Examples:

Corresponding Angles

Definition: When two lines are crossed by another line (which is called the Transversal), the angles in matching corners are called corresponding angles.

Examples:

Inscribed

Definition: An inscribed figure is one that is drawn inside another, usually with the edges touching. For example if you drew a triangle inside a square, the triangle is inscribed in the square.Examples:

Isometry

Definition: A function between metric spaces which preserves distances, such as a rotation or translation in a plane.

Examples:

Transformation

Definition: Moving a shape so that it is in a different position, but still has the same size, area, angles and line lengths.

Examples:

Line of Refleciton

Definition: A transformation where each point in a shape appears at an equal distance on the opposite side of a given line - the line of reflection.Examples:

Mid Point

Definition: A point on a line segment that divides it into two equal partsThe halfway point of a line segment

Obtuse Angle

Definition: An obtuse angle is an angle that is 91 degrees to 179 degrees.

Examples: 1. 168 degrees is an obtuse angle2. 359 degrees is an obtuse angle

Ordered number pair

Definition: Two numbers written in a certain order.

Examples: 1. Usually written in parentheses like this: (4,5) 2.

Parallel Line

Definition: A parallel line is a line that can keep going on and on next to another line and they will never run into each other.

Examples:

Perpendicular

Definition: At an angle of 90° to a given line, plane, or surface.

Examples:

Perpendicular Bisector

Definition: A line which cuts a line segment into two equal parts at 90°.

Examples:

Preimage

Definition: The original figure prior to a transformation (for example, the way a geometric shape looks before being rotated & dilated).Examples:

Reflection

Definition: A Reflection is a transformation in which the figure is the mirror image of the other.

Examples:

Reflex Angle

Definition: An angle whose measure is greater than 180° and less than 360.

Examples:

Right Angle

Definition: A right angle is an angle that measures exactly 90 degrees.

Examples:

Rotation

Definition: A circular movement of a shape.

Examples:

Sector

Definition: A mathematical instrument consisting of two arms hinged at one end and marked with sines, tangents, etc., for making diagramsExamples:

Straight Angle

Definition: A straight angle is an angle that measures 180 degrees.

Examples:

Supplementary Angles

Definition: Either of two angles whose sum is 180°

Examples:

Transformation

Definition: Moving a shape so that it is in a different position, but still has the same size, area, angles and line lengths.

Examples:

Translation

• Definition: Moving a shape, without rotating or flipping it. "Sliding”. The shape still looks exactly the same, just in a different place.

Examples:

Transversal

Definition: A line that cuts across two or more (usually parallel) lines.

Examples:

Vertex

Definition: The common endpoint of two or more rays or line segments.

Examples:

Vertical Angles

Definition: A pair of non-adjacent angles formed by the intersection of two straight lines

Examples: