http://www.ck12.org Chapter 6. Polygons and Quadrilaterals
11.
12.
For questions 13-15, determine the value ofxandythat would make the quadrilateral a parallelogram.
13.
14.
15.
For questions 16-18, determine ifABCDis a parallelogram.
16.A( 8 ,− 1 ),B( 6 , 5 ),C(− 7 , 2 ),D(− 5 ,− 4 )
17.A(− 5 , 8 ),B(− 2 , 9 ),C( 3 , 4 ),D( 0 , 3 )
18.A(− 2 , 6 ),B( 4 ,− 4 ),C( 13 ,− 7 ),D( 4 ,− 10 )
Write a two-column proof.
19.Opposite Angles Theorem ConverseGiven:^6 A∼=^6 C,^6 D∼=^6 BProve:ABCDis a parallelogram
20.Parallelogram Diagonals Theorem Converse