Math Is Fun Forum

emmakatecumbo

Member

Registered: 2017-09-22

Posts: 35

Geometry help

These 6 questions I completed but I got wrong. Could someone please help me get the correct answers? Ill post what my teacher had to comment about my answers down below.

1. 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.

1 should = 5 if they are parallel and had a transversel through them.

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

Explain.

co-interior angles are supplementary and thus 6+4 should = 180. 30 and 60 obviously are

complementary, not supplementary.

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

I have no clue what the answer is for this one.

5. 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

The final answer is 720

6. 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. 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.

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.

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

I believe the answer for this would be 90 x.

Teachers comments on my work :
#1-3    Now state whether or not the lines are parallel

#5-6    What is the measure of ONE angle?

#7    and what is the OTHER possible scale factor for these measurements?

#10    90x means 90*x...  that is incorrect... is there another relationship between 90 and x?

Last edited by emmakatecumbo (2017-10-29 10:51:31)

alter ego

Member

Registered: 2012-03-30

Posts: 29

Re: Geometry help

Again no diagram for the first three.

You have correctly found the angle sum for the polygons. In a regular polygon all the angles will be equal, so now calculate one of them.

Your scale factor is correct for small shape as a fraction of the large shape.  I think the second answer is for large as a multiple of the small.

In the last a minus sign is needed.  I'm not seeing that.

What course are you studying?

A

iamaditya

Member

From: Planet Mars

Registered: 2016-11-15

Posts: 821

Re: Geometry help

Hi alter ego,

You need to post a diagram for this as well as the other thread. I think you missed it.

---

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There is no substitute to hard work
All of us do not have equal talents but everybody has equal oppurtunities to build their talents.-APJ Abdul Kalam

emmakatecumbo

Member

Registered: 2017-09-22

Posts: 35

Re: Geometry help

How do you post the diagram

zetafunc

Moderator

Registered: 2014-05-21

Posts: 2,436

Website

Re: Geometry help

Hi emmakatecumbo,

You can upload the image using this link, and then post the link to your image back here: https://postimages.org/

emmakatecumbo

Member

Registered: 2017-09-22

Posts: 35

Re: Geometry help

https://postimg.org/image/7zi8v9g2hn/