In the given parallelogram ABCD:
CD=5x-18
BC=3x-6
AB=2x+12
From the properties of parallelogram: The opposite sides of parallelogram are equal
Pair of opposite sides are:
AB & CD
BC & DA
Opposite sides are equal:
[tex]\begin{gathered} AB=CD \\ 2x+12=5x-18 \\ 5x-2x=12+18 \\ 3x=30 \\ x=\frac{30}{3} \\ x=10 \end{gathered}[/tex]x = 10
Substitute the value of x = 10 in the expression of BC
BC = 3x - 6
BC = 3(10) - 6
BC = 30 - 6
BC = 24
Opposite sides are equal: BC = DA
BC = 24 = DA
DA = 24
Answer: DA = 24