Question

Which biconditional is not a good definition?
A. Two angles are supplementary if and only if the sum of their angles measure 180.
B. Two angles are vertical angles if and only if they are nonadjacent and are formed by two intersecting lines.
C. Two angles from a linear lair if and only if the angles are adjacent.
D. The sum of two angles is 90 if and only if they are complementary

Answer 1

What you got?

Answer 2

I think it's B

Answer 3

why?

Answer 4

Because the word nonadjacent? It's the only one that doesn't make complete sense.

Answer 5

So it's not b?

Answer 6

Really I am not sure.
You choose, I check ;)

Answer 7

:(

Answer 8

Don't be sad!

Answer 9

It is not the end of the life!

Answer 10

Let's think by Exclusion! ok?
what about A ?

Answer 11

A is correct

Answer 12

It's definition is anyways. supplementary angles equal 180

Answer 13

Nice!
b?

Answer 14

ok let b now
c?

Answer 15

Im not sure about c

Answer 16

I know it has to have adjacent pairs whose uncommon sides are opposite rays

Answer 17

And I know d is correct because complementary angles equal 90

Answer 18

@mathmate

Answer 19

So A and D are correct, so we are thinking between C and B!

Answer 20

@triciaal

Answer 21

Two angles from a linear lair if and only if the angles are adjacent.
pair or lair?

Answer 22

Pair sorry

Answer 23

Ok
That makes sense!

Answer 24

Take a look
http://www.regentsprep.org/regents/math/geometry/gp5/langles.htm
http://www.uhigh.ilstu.edu/math/sondgeroth/geom/07%20geom%20review%2003.htm

then decide

Answer 25

I think it's b because doesn't a vertical angle have to be supplementary?

Answer 26

It was an emergency call.
sorry

Answer 27

Hey hey
I got it
It is C
Forgive me for being late!

Answer 28

@BuckyBarnes

Answer 29

The choice that has not a good definition (insufficient conditions) is C
WHY?
Because this is the correct one:
Two angles form a linear pair if and only if they are adjacent and their non-common sides form a pair of opposite rays.

Answer 30

I hope you got it.

Answer 31

What does nonadjacent mean?

Answer 32

For angles a and b, there are linear pair of angles as the other sides of the angles (AB and BC) form a pair of opposite rays, which does not satisfied in EF and FG (these are not opposite rays)