3.6. Same Side Interior Angles http://www.ck12.org
Guided Practice
- Isl||m? How do you know?
- Find the value ofx.
- Find the value ofxifm^63 = ( 3 x+ 12 )◦andm^65 = ( 5 x+ 8 )◦.
Answers:
- These are Same Side Interior Angles. So, if they add up to 180◦, thenl||m. 113◦+ 67 ◦= 180 ◦, thereforel||m.
- The given angles are same side interior angles. Because the lines are parallel, the angles add up to 180◦.
( 2 x+ 43 )◦+( 2 x− 3 )◦= 180 ◦
( 4 x+ 40 )◦= 180 ◦
4 x= 140
x= 35- These are same side interior angles so set up an equation and solve forx. Remember that same side interior angles
add up to 180◦.
( 3 x+ 12 )◦+( 5 x+ 8 )◦= 180 ◦
( 8 x+ 20 )◦= 180 ◦
8 x= 160
x= 20Practice
For questions 1-2, determine if each angle pair below is congruent, supplementary or neither.
1.^6 5 and^68
2.^6 2 and^63
3. Are the lines below parallel? Justify your answer.
In 4-5, use the given information to determine which lines are parallel. If there are none, write none. Consider each
question individually.
4.^6 AF D and^6 BDFare supplementary
5.^6 DIJ and^6 F JIare supplementary
For 6-11, what does the value ofxhave to be to make the lines parallel?
6.m^63 = ( 3 x+ 25 )◦andm^65 = ( 4 x− 55 )◦
7.m^64 = ( 2 x+ 15 )◦andm^66 = ( 3 x− 5 )◦
8.m^63 = (x+ 17 )◦andm^65 = ( 3 x− 5 )◦
9.m^64 = ( 3 x+ 12 )◦andm^66 = ( 4 x− 1 )◦
10.m^63 = ( 2 x+ 14 )◦andm^65 = ( 3 x− 2 )◦
11.m^64 = ( 5 x+ 16 )◦andm^66 = ( 7 x− 4 )◦