Transcript 8-3 Angle Relationships - Raisin City Elementary School

8-3 Angle
Relationships
Objective: Students identify
parallel and perpendicular
lines and the angles formed
by a transversal.
Vocabulary
 Adjacent
angles- have a common vertex
and a common side, but no common
interior points.
angles- are the nonadjacent
angles formed by two intersecting lines.
2
3
1
4
 Vertical
 Transversal-
is a line that intersects two or
more lines that lie in the same plane.
2
3
1
4
Example 1
Finding Angle Measures
 Use
the diagram to find each angle
measure.
 If
m∠2 = 75°, find m∠4
2
 If
m∠3 = x °, find m∠1
3
1
4
Transversals
 If
two parallel lines are intersected by a
transversal,



corresponding angles are congruent,
alternate interior angles are congruent,
and alternate exterior angles are
congruent.
 If
the transversal is perpendicular to the
parallel lines, all of the angles formed are
congruent 90° angles.
Corresponding
angles
Alternate interior
angles
Alternate exterior
angles
Example 2
Finding Angle Measures of
Parallel Lines Cut by Transversals
 In
the figure, line a ll line b. Find the
measure of each angle.
b
c
a
74°
3
1
4
2
7
6
5
Guided Practice
Page

390
Problems 1-2