Fill in the blanks in the proofs ASAP!!

Question

1. We are given that diagonals AC congruent to BD
2. It can be stated that   because they are opposite sides of a parallelogram.
3. By the Reflexive Property of Congruence, .
4. Thus, ____1_____ by the ____2_____ Congruence Postulate. 
5. Then  because they are corresponding angles of congruent triangles. 
6. Since consecutive angles in a parallelogram are supplementary, .
7. Therefore, using substitution and the definition of congruent angles, the previous statement can be simplified to conclude that  and  are both .   
8. Thus, parallelogram  is a rectangle by definition of a rectangle.   

Select one answer choice for blank 1, and select one answer choice for blank 2.

multiple choice

1. ABC or ABC
2. SSS SAS ASA

Answer 1

I am very sorry that I am having an extremely difficult time following this proof.

So here is q quick summary of the proof...

Parallelogram ABCD, with A in the top left going clockwise...

M = AC intersect BD

It shall suffice to show that angle BAD and able CDA are equal and supplementary.

By SSS:

triangle BAD = triangle DCB

triangle BAD = triangle CDA

By CPCTC:

angle BAD = angle DCB

angle BAD = angle CDA

which by transitive/substitution:

angle DCB = angle BAD = angle CDA

BUT.... angles CDA and BAD are SUPPLEMENTARY

(and at the same time equal, as just proven)

so therefore they must both be 90 degrees.