Math 301 Vocabulary Review (from M 351)
Congruent / Shapes that are identical (same shape, same size)Angles or line segments with the same measure.
Point / An undefined entity in geometry that indicates position, but has no dimension
Line / A set of points that form a straight path extending infinitely in 2 directions
Plane / A flat surface extending infinitely in all directions
Ray / A half-line. A part of a line with an endpoint, extending infinitely in one direction.
Line Segment / A part of a line. A line segment has 2 endpoints and contains the points between the endpoints.
Angle / An angle is formed by two rays with a common endpoint, called a VERTEX.
Acute angle / An angle with a measure < 90 degrees.
Right angle / An angle with a measure = 90 degrees
Obtuse angle / An angle with a measure between 90 and 180 degrees.
Straight angle / An angle with a measure of 180 degrees.
Parallel lines / Two lines in the same plane that do not intersect.
Perpendicular lines / Two lines that intersect to form right angles.
Concurrent lines / Three or more lines that intersect in one common points
Skew lines / Two lines that are not parallel but do not intersect
Figure / A two-dimensional shape with straight sides, contained in a plane
Solid / A three-dimensional shape
Simple figure / A figure whose sides have only their vertices in common.
Closed figure / A figure with no open end points
Polygon / A simple, closed figure
Triangle / A 3-sided polygon
Quadrilateral / A 4-sided polygon
Pentagon / A 5-sided polygon
Hexagon / A 6-sided polygon
Heptagon / A 7-sided polygon
Octagon / An 8-sided polygon
Nonagon / A 9-sided polygon
Decagon / A 10-sided polygon
Dodecagon / A 12-sided polygon
Acute triangle / All three angles measure less than 90 degrees
Right triangle / One angle measures 90 degrees
Obtuse triangle / One angle measures more than 90 degrees
Scalene triangle / No sides are congruent.
Isosceles triangle / Exactly two sides are congruent
Equilateral triangle / All sides are congruent
Similar polygons / Two polygons whose angles are congruent and whose corresponding sides are in proportion (have the same ratio)
Circle / Set of point the same distance from a given point known as the center of the circle. The measure of a circle is 360o.
Chord / A line segment connecting two points on a circle
Diameter / A chord that passes through the center of the circle
Radius / A line segment connecting the center of the circle to a point on the circle
Minor arc / A portion of the circle measuring less than 180o
Semicircle / An arc measuring 1800
Major arc / An arc measuring between 180o and 360o
Central angle / An angle whose vertex is the center of the circle and whose sides are radii of the circle
Inscribed angle / An angle whose vertex is on the circle and whose sides are chords of the circle