✓ Lesson Check

Do you know HOW?

A B ↔ modified eh b with left right arrow above  contains points A and B. C D ↔ modified c d with left right arrow above  contains points C and D. Are A B ↔ modified eh b with left right arrow above  and C D ↔ modified c d with left right arrow above   parallel, perpendicular, or neither? Explain.

1. A ( − 8 , 3 ) , B ( − 4 , 11 ) , C ( − 1 , 3 ) , D ( 1 , 2 ) eh open negative 8 comma 3 close comma b open negative 4 comma 11 close comma c open negative 1 comma 3 close comma d open 1 comma 2 close
2. A ( 3 , 5 ) , B ( 2 , − 1 ) , C ( 7 , − 2 ) , D ( 10 , 16 ) eh open 3 comma 5 close comma b open 2 comma negative 1 close comma c open 7 comma negative 2 close comma d open 10 comma 16 close
3. A(3, 1), B(4, 1), C(5, 9), D(2, 6)
4. What is an equation of the line perpendicular to y = − 4 x + 1 y equals , minus , 4 x plus 1  that contains ( 2 , − 3 ) ? open 2 comma negative 3 close question mark

Do you UNDERSTAND?

5. Error Analysis Your classmate tries to find an equation for a line parallel to y = 3 x − 5 y equals 3 x , minus 5  that contains ( − 4 , 2 ) . open negative 4 comma 2 close .  What is your classmate's error?

   

6. Compare and Contrast What are the differences between the equations of parallel lines and the equations of perpendicular lines? Explain.