Answer:
The given quadrilateral is a parallelogram.
Step-by-step explanation:
If a quadrilateral is a parallelogram , then the opposite sides would be equal.
Here we are going to equate the length of 1 pair of opposite sides to find the value of x and use this value of x to verify whether the other pair of opposite sides are equal.
AB = 6x
BC = 3x
DC = x + 15
AD = 9
Equate AB and CD,
6x = x + 15
5x = 15
x = 3
Now BC and DA should be equal.
BC = 3x = 9
Also DA = 9
As we can see, the other pair of opposite sides are also equal.
Quadrilateral ABCD is a parallelogram if both pairs of opposite sides are congruent.
Hence , the given quadrilateral is a parallelogram.
