Question

ABCD is a parallelogram. Find the length of BC.
А
B
4a - 1
5a - 4
D
с

Answer 1

One property of a parallelogram is that opposite sides are equal in length

Hence,

`\begin{gathered} BC=AD \\ 9z-42=3z-6 \\ 9z-3z=42-6 \\ 6z=36 \\ z=(36)/(6) \\ z=6 \end{gathered}`

Side BC is then calculated as:

`\begin{gathered} 9z-42=9(6)-42 \\ =54-42 \\ =12 \\ \\ \text{Therefore, BC is 12 units} \end{gathered}`