1. Topic: Constructions and Congruence (6.4)
Date:
Topic: Constructions and Congruence (6.4)
Warm-up Find the measure of angle KLM. Is it acute, right, or obtuse? What other ways can we name this angle?
acute

2. Lines that intersect to form right angles (90˚) are called perpendicular lines ( ).
m || n
Parallel lines (||) are coplanar lines that do not intersect.
Noncoplanar lines are called skew lines.

3. are vertical angles and therefore equal in measure.
In the figure, Find G C A B D F E
30˚
60˚
60˚
are vertical angles and therefore
equal in measure.

4. The distance between the endpoints of a segment are called the segment length.
When two line segments are of equal length, they are called congruent.
CONGRUENCE: We use the sign ≅ to denote congruent segments, angles, triangles, and geometric figures.
The same notation is used for congruent angles.

5. We construct congruent segments and angles using a compass:

6. Congruent segments click on for an on-line exampleQ P

7. Congruent angles click on for an on-line example