How was sharecropping used to manipulate blacks in the south?

Sharecropping is a type of farming in which families rent small plots of land from a landowner in return for a portion of their crop, to be given to the landowner at the end of each year. Different types of sharecropping have been practiced worldwide for centuries, but in the rural South, it was typically practiced by former slaves. With the southern economy in disarray after the abolition of slavery and the devastation of the Civil War, conflict arose during the Reconstruction era between many white landowners attempting to reestablish a labor force and freed blacks seeking economic independence and autonomy.

3. parallelogram

step-by-step explanation:

we turn each of our sides into direction vectors

ab=b-a=(3 - 7, 1 - 0) = (-4, 1)

bc=c-b=(1,6)

cd=d-c=(4,-1)

da=a-d=(-1,-6)

we see how the opposite sides have negated direction vectors; this is characteristic of a parallelogram.   we have congruent sides ab=cd and bc=da with unequal lengths because 1^2+6^2 is different from (-4)^2+1^2.   so it's not a square or a rhombus.  

we check the dot product of direction vectors of adjacent sides.   we have

ab dot bc = -4(1) + 1(6) = 2

that's not zero so the sides are not perpendicular.   we've ruled out rectangle.

the direction vectors indicate two pairs of congruent parallel sides, so we choose parallelogram over trapezoid.