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Geometry Section 1.4 Angles and Their Measures. An * angle is t he figure formed by the union of two rays with a common endpoint. The rays are called the ____ of the angle and their common endpoint is the _____ of the angle. sides. vertex.
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An *angle is the figure formed by the union of two rays with a common endpoint.The rays are called the ____ of the angle and their common endpoint is the _____ of the angle. sides vertex
The same angle can be named in different ways:1) 2) 3) by 3 points, with the middle point being the vertex by just the vertex – must have only one angle with this vertex
The same angle can be named in different ways:1) 2) 3) by 3 points, with the middle point being the vertex by just the vertex – must have only one angle with this vertex by using a number placed in the interior near the vertex
Angles are measured using a __________.A common unit used for measuring angles is the ______. Radians and gradients are also used. protractor degree
We write ______to represent the measure of .Postulate 1.3.2: Two angles are congruent iffTick marks are used to indicate congruent angles in a figure. their measures are equal.
We write ______to represent the measure of .Postulate 1.3.2: Two angles are congruent iffTick marks are used to indicate congruent angles in a figure. their measures are equal.
Angles are classified according to their measure.An *acute angle is an angle whose measure is A *right angle is an angle whose measure is between 0 and 90 degrees. exactly 90 degrees.
To indicate a right angle in a figure, place a small square at the vertex.Perpendicular lines are two lines that intersect To indicate that is perpendicular to , we write _________ to form right angles.
An *obtuse angle is an angle whose measure is A *straight angle is an angle whose measure is between 90 and 180 degrees. exactly 180 degrees.
The Angle Addition Postulate is similar to the Segment Addition Postulate.Postulate 1.3.3: Angle Addition Postulate: If S is in the interior of , then
An *angle bisector is the ray which divides an angle into two congruent angles.