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#77 2012-11-02 09:44:34
- bob bundy
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Re: Circles: Chords, Radii, and Arcs
That's ok.
I recommend that you get some practice by drawing a few triangles. Measure the three angles and check they add to 180.
Also try 90-45-45 for example.
Make sure you are clear about equilateral and isosceles triangles.
I've made a diagram with all the correct angles marked.
eg. BOC means the angle at O made by the lines OB and BC. You should have 120 for this.
Hint for Q16.
Split the isosceles triangle BOC in half to make two right angled triangles. Now you can calculate half of BC.
Off to bed now.
Bob 
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
#79 2012-11-02 12:11:24
- bobbym
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Re: Circles: Chords, Radii, and Arcs
Hi zee-f;
That is what I get for 16 also.
In mathematics, you don't understand things. You just get used to them.
90% of mathematicians do not understand 90% of currently published mathematics.
I am willing to wager that over 75% of the new words that appeared were nothing more than spelling errors that caught on.
#81 2012-11-03 04:36:09
- zee-f
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Re: Circles: Chords, Radii, and Arcs
Ok for the question bellow I was really lazy to actually draw the circle and I said the CAB= 23 and it was incorrect then I drew a circle like the one we did yesterday and here's What I Got
AOB = 80
ABO = 50
BAO = 50
CBO = 40
BOC = 100
BCO= 40
Ok So CAB would be 50 degrees
18. If the measure of arc AB is 80 degrees, what is the measure of angle CAB?
Hint: Remember that all the angles in a triangle add up to 180 degrees.
A 13 deg
B 23 deg
C 42 deg
D 50 deg
E 37 deg
F 119 deg
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
#82 2012-11-03 08:54:14
- bobbym
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Re: Circles: Chords, Radii, and Arcs
Hi;
It would help if you could show your drawing.
In mathematics, you don't understand things. You just get used to them.
90% of mathematicians do not understand 90% of currently published mathematics.
I am willing to wager that over 75% of the new words that appeared were nothing more than spelling errors that caught on.
#83 2012-11-03 19:12:11
- bob bundy
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Re: Circles: Chords, Radii, and Arcs
hi zee-f and bobbym,
If it's the same diagram as before, with new angles, then those answers all look good to me.
Bob
ps. What happened to Q17 ?
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
#84 2012-11-04 09:09:44
- zee-f
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Re: Circles: Chords, Radii, and Arcs
Hi,
I get the same drawing the bob bundy drew but the question doesn't really say if it is the same diagram it only says:
18. If the measure of arc AB is 80 degrees, what is the measure of angle CAB?
Hint: Remember that all the angles in a triangle add up to 180 degrees.
A 13 deg
B 23 deg
C 42 deg
D 50 deg
E 37 deg
F 119 deg
I get D 50 degrees
also I got 17 correct it said 17. If the measure of arc AB is 75 degrees, what is the measure of arc BC?(I answered F)
A 27 deg
B 54 deg
C 100 deg
D 180 deg
E 160 deg
F 105 deg
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
#85 2012-11-04 09:42:00
- bob bundy
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Re: Circles: Chords, Radii, and Arcs
hi zee-f
18D and 17F. Both look correct to me. Well done.
Looking back, it seems all these questions use the same diagram from post 52.
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
#86 2012-11-04 10:46:23
- zee-f
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Re: Circles: Chords, Radii, and Arcs
Thank you guys 
I am still correcting #8 and #19
I choose#8- F and it was incorrect
8. If I drew a line segment from A to C, and the radius of circle M was 1, what would line segment AC be?
A sqrt 7
Bsqrt 2
Csqrt 8
D sqrt 13
E sqrt 4
F sqrt 3
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
#87 2012-11-04 12:19:14
- bobbym
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Re: Circles: Chords, Radii, and Arcs
Hi;
I would choose E and then shoot the questioner!
In mathematics, you don't understand things. You just get used to them.
90% of mathematicians do not understand 90% of currently published mathematics.
I am willing to wager that over 75% of the new words that appeared were nothing more than spelling errors that caught on.
#89 2012-11-04 12:22:51
- bobbym
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Re: Circles: Chords, Radii, and Arcs
Hi;
Looking at the diagram I see that line segment AC is a diameter. If the radius is 1 then the diameter is 2. Which answer equals 2?
In mathematics, you don't understand things. You just get used to them.
90% of mathematicians do not understand 90% of currently published mathematics.
I am willing to wager that over 75% of the new words that appeared were nothing more than spelling errors that caught on.
#90 2012-11-04 19:23:39
- bob bundy
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Re: Circles: Chords, Radii, and Arcs
hi
For question 8 don't you want the diagram below?
I thought you had this one ciorrect back at post 4.
Bob
ps. What's the question for 19 ?
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
#92 2012-11-05 03:09:47
- zee-f
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Re: Circles: Chords, Radii, and Arcs
19. If I created an imaginary point on arc AC named D, and drew line segments from points A and C to D, what would the measure of angle ADC be?
I choose F and it was incorrect.
A 60 deg
B 7.5 deg
C 30 deg
D 15 deg
E 90 deg
F 120 deg
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
#93 2012-11-05 03:31:06
- bob bundy
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Re: Circles: Chords, Radii, and Arcs
hi zee-f
Look below and check that I've got the diagram right.
120 would be the arc BC.
Arc ADC is 180 because AC is a diameter; it doesn't matter where D is.
But the question asks for angle ADC.
What does that look like?
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
#95 2012-11-05 05:16:41
- bob bundy
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Re: Circles: Chords, Radii, and Arcs
Well what other choice is there? The questioner seems to like using the same diagram over and over so, in the absence of any other instruction, I think you've got to. The 'right' answer is in there amongst the multi-choices.
What do you think it is?
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
#98 2012-11-05 05:40:12
- bob bundy
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Re: Circles: Chords, Radii, and Arcs
It just means choose any point on the circumference between A and C
So look again at my diagram.
We want the angle ADC. It's not 30. Again my diagram is accurate. Time for that protractor again I think.
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
#100 2012-11-05 05:43:31
- zee-f
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Re: Circles: Chords, Radii, and Arcs
I drew a circle and the first half is 30, 30, 120 the second is 60 60 60 it looks exactly like your triangle in the diagram but cut in half at 120
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3