Suppose you surveyed a group of students to see how many CDs they owned. The results are displayed in the histogram shown below. Based on this histogram, how many students were surveyed?
15
10
5
0
5-8
9-12
13-16 17-20
A. 11
B. 28
C. 33
D. 43

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.

e) none of the above because the measure of angle cba is 101°

step-by-step explanation:

f

b

step-by-step explanation: