Math Is Fun Forum

ooooh yeah I remember that from my algebra course

I started the next lesson about Circumference and Arc Length and I got all the 18/20
I am stuck on the 2 questions I got incorrect :

I choose C it was incorrect

What is the circumference of the circle if the radius is:

10. (x + y)pi

A (x+y)/7
B (x+y)/5
C(x+y)/1
D(x+y)/2
E (x+y)/3
F (x+y)/8

So I know the the formula for the circumference of a circle is 2(pi)(r)

So it would be 2(pi)*((x + y)pi) right? but then what do I do ?

I choose A it was incorrect I am still working on the correction
What is the length of the arc if
15. r=y n=x
A  x*y*pi/90
B x*y*pi/30
C x*y*pi/45
D x*y*pi/27
E  x*y*pi/180
F  x*y*pi/115

L =
(n/360)(2(PI)r) where L = length, n = degree measure of arc, and r = radius of the circle.

Thank you for the help!

I said #102 before seeing post #101

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

I think it is 30 degrees

So i use the same diagram from #18?

That's weird I think I choose 8-F by excedent  because that is not what I got earlier

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

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

Thank you so much for all the help and time !:)