9. x = 9 units
10.

11.

12.x =10 units
13. x= 1 unit
14.

15.

16.

Explanation:
9.
Opposite sides of a parallelogram are equal to each other.
Therefore
2x-5 = 13
⇔2x = 13+5
⇔

⇔x = 9 units
10.
Sum of adjacent angles of parallelogram is
.
Therefore

⇔

⇔

⇔

⇔

11.
Opposite angles of a parallelogram are congruent(equal).
Therefore

⇔

⇔

⇔

12.
Opposite sides of a parallelogram are congruent.
Therefore
2x-11=9
⇔2x = 11+9
⇔2x=20
⇔

⇔x =10 units
13.
Opposite sides of a parallelogram are congruent (equal).
Therefore,
17x+1=18
⇔17x =18-1
⇔x= 1 unit
14.
Opposite angles of a parallelogram are congruent(equal).
Therefore,

⇔

⇔

⇔

15.
Sum of adjacent angles of parallelogram is
.
Therefore

⇔

⇔

⇔

16.
Opposite angles of a parallelogram are congruent(equal).
Therefore,

⇔

⇔

⇔
