Download Chapter 12 and Chapter 3

Chapter 12 and Chapter 3
Geometry Terms
Adjacent and Vertical Angles
Two angles are adjacent angles
when they share a common
side and have the same vertex.
Two angles are vertical angles when they are
opposite angles
formed by the intersection of two lines.
Vertical angles
are congruent angles, meaning they have the
same measure.
Complementary and Supplementary
Angles
Two angles are complementary
angles when the sum of their
measures is 90°.
Two angles are supplementary angles
when the sum of their
measures is 180°.
Corresponding Angles
A line that intersects two or more lines
is called a transversal. When
parallel lines are cut by a transversal,
several pairs of congruent angles
are formed.
When a transversal intersects
parallel lines, corresponding
angles are congruent.
Alternate Interior Angles
When two parallel lines are cut by a
transversal, four interior angles are
formed on the inside of the parallel lines
and four exterior angles are formed on
the outside of the parallel lines.
When a transversal intersects parallel lines, alternate interior angles
are congruent and alternate exterior angles are congruent.
Alternate Exterior Angles
When two parallel lines are cut by a transversal, four interior angles are
formed on the inside of the parallel lines and four exterior angles are formed
on the outside of the parallel lines.
When a transversal intersects parallel lines, alternate interior angles
are congruent and alternate exterior angles are congruent.
Interior and Exterior Angles
The angles inside a polygon are called interior angles. When the sides of a
polygon are extended, other angles are formed. The angles outside the
polygon that are adjacent to the interior angles are called exterior angles.
Interior Angle Measures of a Triangle
Words: The sum of the interior angle
measures of a triangle is 180°.
Algebra: x + y + z = 180
Exterior Angle Measures of a
Triangle
The sum of two interior
angles will always equal
the exterior angle of the
third angle
The sum of the
exterior angles of a
polygon will always
equal 360 degrees
Putting it Together