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## #1 2013-06-24 03:42:13

demha
Member
Registered: 2012-11-25
Posts: 195

### Geometry Review

So I just need help to make sure I got my answers right and there are also a few I was not too sure on how to do them, so help with those would be great

SO numbers 1 - 4 are referring to the image. It's only numbers 1 - 3 I'm not understanding too well on how to answer them. I would appreciate help with the first one (like a walk through) to help me understand. thanks!
REVIEW:

1.
Q. Refer to the image at the right. If angle 1 is 30 degrees, and angle 5 is 70 degrees, are the two lines parallel? Explain.

A.

2.
Q. Refer to the image at right. If angle 2 is 30 degrees and angle 4 is 60 degrees, are the lines parallel? Explain.

A.

3.
Q. Refer to the image at right. If angle 2 and angle 6 are both 70 degrees, are the lines parallel? Explain.

A.

4.
Q. Refer to the image at right. If the lines are parallel, and angle 4 is 50 degrees, what is the measure of angle 6?

A. Angle 6 will be 130 degrees.

5.
Q. What is the measure of the inner angle of a regular hexagon? Show your work (and be sure to explain anything you deem necessary to make sure your work is clear.)

A. A hexagon has 6 sides.
180 x 6 = 1080
The sum of the angles of deviation is 360
SO
1080  360 = 720

6.
Q. What is the measure of the inner angle of a regular decagon? Show your work (and be sure to explain anything you deem necessary to make sure your work is clear.)

A. A decagon has 10 sides.
180 x 10 = 1800
The sum of the angles of deviation is 360
SO
1800  360 = 1440

7.
Q. Polygon A has sides of 4, 3, 5, and 3. Polygon B has sides of 8, 6, 10, and 6. What are the two possible scale factors here? Explain.

A.
To get my scale factor, I will need to divide the two polygons. This is how I will do it along with the answers for each number:
4 / 8 = 1/2
3 / 6 = 1/2
5 / 10 = 1/2
3 / 6 = 1/2

So now we know the scale factor is 1:2.

8.
Q. A triangle has angles of 34 degrees, 56 degrees, and 90 degrees. It also have sides of 6, 8, and 10. Which side is across from which angle?

A.
Side 6 will be across angle 34.
Side 8 will be across angle 56.
Side 10 will be across angle 90.

9.
Q. A triangle has one angle measuring 52 degrees, and one angle measuring 18 degrees. What is the measure of the third angle?

A. The third angles measurement is 110 degrees.

10.
Q. A right triangle has a 90 degree angle, and an angle x. What will the measure of the third angle be?

A. I believe the answer for this would be 90  x.

Last edited by demha (2013-06-24 03:43:28)

"The thing about quotes on the Internet is you cannot confirm their validity"
~Abraham Lincoln

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## #2 2013-06-24 03:49:57

ShivamS
Member
Registered: 2011-02-07
Posts: 3,648

### Re: Geometry Review

1. No, as 1 should = 5 if they are parallel and had a transversel through them.

2. Also no, as co-interior angles are supplementary and thus 6+4 should = 180. 30 and 60 obviously are complementary, not supplementary.

3. Yes.

4. They are co-interior and thus supplementary. therefore, 50+x=180 and x=130. This, angle 6 is 130 degrees.

5. A bit of confusion. Do you mean to ask how much is each interior angle? If yes, the sum of interior angles in a regular polygon are the # of triangles 8 180 or (n-2)*180. 4*180 = 720 degrees. That is the sum of interior angles. each one is 720/n = 120 degrees.

6. Same concept as 5. 8*180 = 1440. Divide that by 10 and it is 144.

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## #3 2013-06-24 04:10:50

bob bundy
Moderator
Registered: 2010-06-20
Posts: 7,836

### Re: Geometry Review

hi demha

Have a look back to

http://www.mathisfunforum.com/viewtopic.php?id=19401

post 6.

When you have parallel lines the four acute angles are all the same and similarly the four obtuse ones are the same.

That should help with Q 1 2 and 3.

7.
Q. Polygon A has sides of 4, 3, 5, and 3. Polygon B has sides of 8, 6, 10, and 6. What are the two possible scale factors here? Explain.

A.
To get my scale factor, I will need to divide the two polygons. This is how I will do it along with the answers for each number:
4 / 8 = 1/2
3 / 6 = 1/2
5 / 10 = 1/2
3 / 6 = 1/2

So now we know the scale factor is 1:2.

That's good but the question says two possible scale factors.  You've given the small to large so the other will be ???

8.
Q. A triangle has angles of 34 degrees, 56 degrees, and 90 degrees. It also have sides of 6, 8, and 10. Which side is across from which angle?

A.
Side 6 will be across angle 34.
Side 8 will be across angle 56.
Side 10 will be across angle 90.

Correct

9.
Q. A triangle has one angle measuring 52 degrees, and one angle measuring 18 degrees. What is the measure of the third angle?

A. The third angles measurement is 110 degrees.

Correct

10.
Q. A right triangle has a 90 degree angle, and an angle x. What will the measure of the third angle be?

A. I believe the answer for this would be 90  x.

Correct

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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## #4 2013-06-24 04:15:41

ShivamS
Member
Registered: 2011-02-07
Posts: 3,648

### Re: Geometry Review

Is this the compuhigh stuff again?

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## #5 2013-06-24 05:19:40

bob bundy
Moderator
Registered: 2010-06-20
Posts: 7,836

### Re: Geometry Review

Shivamcoder3013 wrote:

Is this the compuhigh stuff again?

Looks like it.

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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## #6 2013-06-24 10:33:05

demha
Member
Registered: 2012-11-25
Posts: 195

### Re: Geometry Review

7.
Would it be 2:1?

"The thing about quotes on the Internet is you cannot confirm their validity"
~Abraham Lincoln

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## #7 2013-06-24 11:07:48

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,030

### Re: Geometry Review

Yup!

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #8 2013-06-25 06:55:33

demha
Member
Registered: 2012-11-25
Posts: 195

### Re: Geometry Review

Thanks guys!

"The thing about quotes on the Internet is you cannot confirm their validity"
~Abraham Lincoln

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