Transcript Geometry Section 1.4

Geometry
Section 1.4
Measure and classify Angles
Terms
• Angle consists of two different rays
with the same endpoint
vertex
side
• To name angles, either name with 3
points (point at the vertex in the
middle), or name with the vertex point.
•See mimio example
• To measure use protractor
•See mimio example
Classifying angles
• Acute angle measures more than 0
degrees, but less than 90 degrees
• Right angle measures 90 degrees
• Obtuse angle measures more than 90
degrees but less than 180 degrees
• Straight angle measures 180 degrees
Angle Addition Postulate
• If P is in the interior of angle RST, then
the measure of angle RST is equal to the
sum of angle PST and angle RST
•See mimio example
Examples
• Page 29
•Problems #23, 25
Terms
• Two angles are congruent if they have
the same measure
• Angle bisector is a ray that divides an
angle into two angles that are
congruent
Examples
• Page 30
• Problem 41
Assignment
• Section 1.4
• Page 28
• Problems # 4, 8 – 40 even, 56 - 60