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#1 2019-01-30 04:30:22

Registered: 2018-10-17
Posts: 14

Geometry Review Help pls!

Please help!

1. If I have two points, A and B, name at least four geometric elements taught in Lesson 1 that I can create with only the two points. (For example, the name of a line through points X and Y would be written ln_XY.)

You do need 4 names such as ln_XY.  (Hint:  You are not looking for 4 different kinds of elements, just 4 different elements that are named.)
my answer, AB; In_AB;  Is_AB;  ry_AB

my teacher response -" You have all 3 types of elements, but only 4 of the names:  ln_AB, ls_AB, ry_AB.  (The points are already given.)"

2a.Write a counterexample for the converse of "Cats make great pets."

My answer, converse: If it’s a great pet, then it’s a cat.
I don't know the counterexample though?

2b.Write a counterexample for the converse of "Cars have four wheels."

My answer, Converse:  If it has four wheels, then it’s a car.
again, idk the counterexample

my teacher response, "You have the correct converses, but not the correct counterexamples."

3. An angle exists that is complementary to angle g on one side.  On the other side, the angle is supplementary to angle h. The sum of the three angles is 200°. What is the measure of this common angle?  (Show your work.)

My answer, 70 is the measure of the common angle.

I added 90(g) to 180(h) and got 270. I know the sum of all three angles is 200. So I subtracted 70 to reach 200. I then know the measure of the common angle is 70 because that's what I have left over.

(g) + (h) = 200 - what's left over after 200 (70)

my teacher response,"The angles for g and h do not equal 90 and 180.  If we call the common angle c, this says that g and c are complementary angles, so what do that add up to?  Angles h and c are supplementary, so what do they add up to?  It might help to show your work using the names for the three angles as g, h, and c."

Last edited by Lauren1415 (2019-01-30 09:54:34)


#2 2019-02-02 16:54:43

Registered: 2016-02-01
Posts: 115

Re: Geometry Review Help pls!

Sorry for the delay, but I think no one has answer your question because it is repetitive and very simple. However, the answer goes as follows:

1- This question is very easy and you can find the four geometric object in your book (there are many of them).

2-Your answer about the converse in this question is correct (the converse of a conditional statement is obtained by reversing the order of its hypothesis and conclusion). However, the counterexample is the example which disproves the related statement and in your question for case (a) the counterexample is "Dog is a great pet, but it is not cat". And the counterexample for (b) is "pram has four wheels, but it is not a car".

3- You have to solve the following equations simultaneously:

where c is the common angle, so we have:

now from the first and second equations we have:

so your numerical answer for the value of the angle c is correct, However, your reasoning is not correct since
. I hope this will help.

Last edited by Grantingriver (2019-02-02 17:02:54)


#3 2019-02-05 17:19:46

Registered: 2018-10-17
Posts: 14

Re: Geometry Review Help pls!

Thank you


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