The figure is a parallelogram. one diagonal measures 28 units.
is the figure a rectangle? explain.
a. no, it is not a rectangle because the diagonals are congruent.
b. no, it is not a rectangle because the sides of the parallelogram do not meet at right angles.
c. yes, it is a rectangle because the diagonals are congruent.
d. yes, it is a rectangle because the sides of the parallelogram do meet at right angles.

B. No, it is not a rectangle because the sides of the parallelogram do not meet at right angles.

Step-by-step explanation:

Law of cosines: a^2 = b^2 +c^2 - 2*b*c*cos(A)

Let's call

a = the side which is 28 units length

b = the side which is 21 units length

c = the side which is 20 units length  

A = the angle formed between sides b and c

Solving the formula for A, we get

a^2 = b^2 +c^2 - 2*b*c*cos(A)

2*b*c*cos(A)  = b^2 +c^2 - a^2

cos(A)  = (b^2 +c^2 - a^2)/(2*b*c)

A = arccos[(b^2 +c^2 - a^2)/(2*b*c)]

A = arccos[(21^2 +20^2 - 28^2)/(2*21*20)]

A = 86.1°

3.4 pizzas

step-by-step explanation:

given is a scatter plot showing number of pizzas sold during weeks for different issues of coupon

y represents number of pizzas sold and x number of coupons issued

y is marked verticaly and x horizontally

the trend line is given as

y =3.4x+43

this says that even when no coupon is issued pizzas sold will be 43

and rate of change of pizza sold for 1 unit of coupon = slope = 3.4

i.e. when x increases by 1 unit y increases by 3.4 units

hence for each additional coupon issued 3.4 pizzas more will be sold

step-by-step explanation: