http://www.ck12.org Chapter 6. Polygons and Quadrilaterals
Vocabulary
Aparallelogramis a quadrilateral with two pairs of parallel sides.
Guided Practice
1.SANDis a parallelogram,SY= 4 x−11 andY N=x+10. Solve forx.
- Find the measures ofaandbin the parallelogram below:
- Ifm^6 B= 72 ◦in parallelogramABCD, find the other three angles.
Answers:
- Because this is a parallelogram, the diagonals bisect each other andSY∼=Y N.
SY=Y N
4 x− 11 =x+ 10
3 x= 21
x= 7- Consecutive angles are supplementary so 127◦+m^6 b= 180 ◦which means thatm^6 b= 53 ◦.aandbare alternate
interior angles and since the lines are parallel (since its a parallelogram), that means thatm^6 a=m^6 b= 53 ◦.
3.m^6 D= 72 ◦as well, because opposite angles are congruent.^6 Aand^6 Care supplementary with^6 D, som^6 A=
m^6 C= 108 ◦.
Interactive Practice
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/113030