Question

Look at the quadrilateral shown below.

Answer 1

Terra writes the following proof for the theorem, If the diagonals of a quadrilateral bisect each other, the quadrilateral is a parallelogram.
Terra's proof
1. AO = OC because it is given that diagonals bisect each other.
2. BO = OD because it is given that diagonals bisect each other.
3. For triangles AOB and DOC, angle 1 is equal to angle 2 as they are supplemental angles.
4. Therefore, the triangles AOB and DOC are congruent by SAS postulate.
5. Similarly, triangles AOD and BOC are congruent.
6. By CPCTC, angle ABD is equal to angle BDC and angle ADB is equal to angle DBC.
7. As the alternate interior angles are congruent the opposite sides of quadrilateral ABCD are parallel.
8. Therefore, ABCD is a parallelogram.
Which is the first incorrect statement in Terra's proof?

Answer 2

Which is the first incorrect statement in Terra's proof?

Answer 3

Select one:
a. Statement 2
b. Statement 3
c. Statement 1
d. Statement 4

Answer 4

I thinks it b but im not sure

Answer 5

B - Angels 1 and 2 are not supplementary they are vertical angles

Answer 6

Angles not Angels...

Answer 7

is he correct

Answer 8

why do I get the feeling that you haven't put enough effort to figure this one out?

Answer 9

I got it