Question

Please correct my answers. MEDAL AND FAN!!!!!

19. A
20. A
21. B
22. B

Answer 1

This is the picture

Answer 2

19) is incorrect. What about

Answer 3

Is 19 the only one that is incorrect?

Answer 4

29) is incorrect. What about

Answer 5

What?

Answer 6

Sorry. *20

Answer 7

I believe 21 is correct.

Answer 8

Are they all wrong?

Answer 9

And 22?

Answer 10

I believe 22 is correct.

Answer 11

Sketch for 21.

Answer 12

so.......

Answer 13

They are all B

Answer 14

?

Answer 15

Correct

Answer 16

All good?

Answer 17

yep

Answer 18

Can you correct my work again?

Answer 19

Post a new queation and I'll be glad to have a look at it.

Answer 20

There is no requirement in the question that the quadrilateral be convex. In a polygon with 4 angles, angles that are not consecutive can be considered to be opposite.

Answer 21

Problem 20 states:
two pairs of opposite angles are congruent
You showed an example with a concave polygon with ONE pair of angles congruent.
You have not shown a proper counterexample to dismiss the statement of problem 20.

Answer 22

In problem 20, the answer is "Suffucient".

Answer 23

Problem 19. Insufficient.
Counterexample: an isosceles trapezoid.

Problem 20. Sufficient.

Problem 21. Insufficient.
Counterexample: an isosceles trapezoid.

Problem 22. Insufficient.
Counterexample: a non-rhombus kite.

Answer 24

B
A
B
B

Answer 25

Is correct?

Answer 26

So @mathstudent55 , I suppose you would also agree that the following quadrilateral is parallelogram?

Answer 27

@ospreytriple
In response to your last response:
1. These problems deal with convex polygons, so your figure is not illustrative of such a case. Even if you don't see any specific mention of it, we are dealing only with convex polygons.
2. More importantly, we are dealing with Problem 20. You even drew this figure (see below) when you were discussing problem 20. Problem 20 is about 2 pairs of opposite angles congruent, but your figure only shows one pair of congruent angles. That is why I said your figure was not a good counterexample for two pairs of opposite angles.

3. With problem 19, about one pair of congruent angles, I definitely agree with you that that is insufficient info to prove the quadrilateral is a parallelogram.

Answer 28

@OM14forever
Yes, that is correct.
19 B
20 A
21 B
22 B