The side [tex]BC[/tex] represents the base of the parallelogram.
How to analyze a parallelograms
In this question we must analyze a particular quadrilateral based on their inherent characteristics. Quadrilaterals are figures formed by four sides and four internal angles so that the sum of the latter equals 360°.
Parallelograms are quadrilaterals with two pairs of parallel sides of equal lengths, each pair is not parallel to its counterpart. Like any quatrillateral, it can be represented in terms of its base and height.
According to the image given, the side [tex]BC[/tex] and, likewise, the side [tex]AD[/tex] represent the base of the parallelogram. In a nutshell, the side [tex]BC[/tex] represents the base of the parallelogram. [tex]\blacksquare[/tex]
To learn more on parallelograms, we kindly invite to check this verified question: https://brainly.com/question/1563728
