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Lesson 5-2 Special new

Page history last edited by Math in a Box - Susan Johnsey gm 2 years, 7 months ago

 

Lesson 5-2  Special       

 

1.  RECALL  from Chapter 3 we studied angles created by parallel lines.

     RECALL a Z shape or N shape is created by 2 Alternate Interior angles.  Z  N See the 2  angles in each letter.

     LOOK for them below. If they are congruent then two of the lines (creating those angles) are parallel.

2.  Also recall if 2 lines are PERPENDICULAR to a third line then

     the 2 lines must be parallel to each other.    |__|

                                                                           

    CLICK the WIKI tab above to return to the home.

 

Do NOT let your mouse  enter the box (on tablet do not click box) until you are ready for the answer.  

 

Place your mouse over the box (for tablets please click the box) that you are studying and

      the answers should appear in a few seconds.

 

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Recall the red arrows indicate parallel lines and

      the red sticks indicate congruent (equal) line segments (sides).

 

Decide if these are parallelograms
and if they are then how do you know?
You must know the 4 theorems
and the definition of parallelogram.

To try these again click
REFRESH or RELOAD the web page.

              
              
Susan O. Johnsey www.mathinabox.com Math in a Box 2007

In problem 9 above  do you see the N or Z shape that the alternate interior angles create.   When they are congruent then we know we have parallel lines.   See the two angles with one arc on them.   And see the two angles with the two-arcs on them.  They are congruent alternate interior angles thus we have two pair of parallel lines.