6.2
Theorem 6-1
Opposite sides of a parallelogram are congruent
Theorem 6-2
Opposite angles of a parallelogram are congruent
Theorem 6-3
The diagonals of a parallelogram bisect each other
Theorem 6-4
If three (or more) parallel lines cut of congruent segments on one transversal, then they cut off congruent segments on every transversal
Example Theroem 1
180-53= x
127= x
The angle opposite of the angle with 53 degrees, is 53 degrees. The missing angle, x, is 127, and so is the angle opposite of it.
Example Theorem 2
3x + 2 = 14
3x = 12
X = 4
3(4) + 2 = 14
Example Theorem 3
Number 18
PT= x + 2 and TR= y
QT= 2x and TS= y + 3
x + 2 = y
2x = X + 2 + 3
X = 5
(5) + 2 = y
Y= 7