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°

1 x=22.52

2: 65/39=604+39x

65x-39x=604

26x=604

x=604/26

×=23.23

on monday rodney ate 1/4th of the sandwich = 3/12

on tuesday he ate 1/3rd of the sandwich = 4/12

therefore in total he has eaten = 3/12 + 4/12 = 7/12

thus we can say that he has eaten 7/12 of the sandwich on monday and tuesday alltogether.

happy to

pls mark as brainliest.