Oh, well done. I'm so pleased. Both correct in my opinion.
Bob
]]>15. r=y n=x
#15- My new answer is (E) x*y*pi/180
I pretended that x was 1 and said that
(1/360 * 2= 1/180) then put the x back and multiplied. I get x*y*pi/180.
#10- OK sense I know that c=π*d and D= c/π
I am going to divide the circumference by PI So I will get(x+y)π/π , and
π/π = 1 so I am left with (x+y) and to get the radius I am going to divide by two and my answer is (x+y)/2.
Thank you,
]]>Very well done for getting 18/20 at first attempt. That's really good!
I can see where you went wrong here with Q15, so I'll do it first.
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
With these problems I first work out the whole circumference, and then work out the fraction for the arc.
So cancel a 2 top and bottom and it's done.
Now for question 10.
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)/8So 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 ?
What you have done is exactly right so something else is wrong here.
If the radius has a pi in it, the circumference will collect another, giving a pi squared. None of the answers looks right.
If it's a mis-print I can make sense of it. Try this:
What is the radius of the circle if the circumference 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
This way round it makes sense and one of the answers works.
Bob
]]>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.
I choose D
20. If line segment BC has a length of 24, and line segment AB has a length of 18, what is the radius of the circle?
A 18
B 38
C 6
D 15
E 4
F 29
By my reckoning only Q20 to go or have you done that?
Bob
]]>Bob
]]>Amongst all your answers, you have said it correctly, but I don't want you to get it by luck, I want you to be sure.
So, looking at my multi-coloured diagram, what is angle D every time?
Bob
]]>I've added a few more possibilities in different colours.
But in a way you're right because the angle at D is always ...... ?
Bob
]]>