basic definitions in geometry
DESCRIPTION
Basic Definitions in Geometry. Acute Angle. An angle that measures between 0 and 90 degrees. Right Angle. Angle that measures 90 degrees and formed by perpendicular lines. Obtuse Angle. An angle that measures between 90 and 180 degrees. Straight Angle. - PowerPoint PPT PresentationTRANSCRIPT
Basic Definitions in Geometry
Acute Angle
• An angle that measures between 0 and 90 degrees.
Right Angle
• Angle that measures 90 degrees and formed by perpendicular lines.
Obtuse Angle
• An angle that measures between 90 and 180 degrees.
Straight Angle
• An angle that measures 180 degrees.
Reflex Angle
• An angle that measures between 180 and 360 degrees.
Complementary Angle
• Two angles that add up to 90 degrees.
Supplementary Angles
• Two angles that add up to 180 degrees.
Equilateral Triangle
• A triangle that has 3 equal sides.
Equiangular Triangle
• A triangle that has 3 equal angles and each measures 60 degrees (sum is 180).
Scalene Triangle
• Triangle with different sides and angles.
Isosceles Triangle
• A triangle that has two equal sides and two equal base angles.
Vertical Angles
• Two angles in which the sides of one angle are opposite rays to the sides of the second angle.
Adjacent Angles
• Two angles having a common vertex and a common side, but do not have any interior points in common.
Line Segment
• 2 points called endpoints and all of the points in between them.
Ray
• A part of a line that consists of a point on the line, called the endpoint, and all of the points on one side of the line.
Opposite Rays
• Two rays of the same line with a common endpoint and no other points in common.
Collinear
• A set of points all lying on the same straight line.
Midpoint
• The point of a line segment that divides it into 2 congruent (equal) parts.
Bisector
• A line, ray, or segment which divides a segment into 2 congruent parts.
Perpendicular Lines
• Two lines that intersect to form right angles.
Altitude
• The perpendicular segment from a vertex of a polygon to the opposite side.
Median
• A segment that joins any vertex of a triangle to the midpoint of the opposite side.