Which of the following are not necessary when proving that the diagonals of
a rectangle are congruent? check all that apply.
a. opposite sides are perpendicular.
o
b. all obtuse angles are congruent.
o
c. all right angles are congruent.
o
d. opposite sides are congruent.

Jeffery conducted a survey in his school and found that 30 of the 50 eighth grade students' favorite subject is mathematics. based on the results, jeffery concluded that out of the 200 students in his school, 120 students' favorite subject is mathematics. select the statement that is true about jeffery's conclusion. a. jeffery's conclusion is not valid because the sample was biased since only 200 students were surveyed. b. jeffery's conclusion is valid because the sample was random since all of the students were eighth grade students. c. jeffery's conclusion is valid because the sample was random. d. jeffery's conclusion is not valid because the sample was biased since all of the students were eighth grade students.

Measures of the angle of r, 31 s (x+4) t (3x+9)

Ming says that 0.24 > 1/4 because 0.24= 2/4. which best explains mings error