What's the arc length of this section of a circle?
93089
This seems like a homework problem, so I'll give a few hints.\n\nThe arclength is radius times the angle subtended.\n\nTo find the angle subtended, consider the isosceles triangle created inside the circle where the chord is the hypotenuse and the radius of the circle is the two other legs. \n\nSince the isosceles triangle created is not a right triangle you need to use a specific formula to find the angle "C" subtended by the chord.
838513
Sigh - first guy had it right, but didn't explain it all.  \nPi = 3.14- all you need for the problem\nRadius= half the diameter of your circle. You find the midpoint and measure from there to the side of the circle, in any direction. Most problems give you the radius. or at least show you the midpoint on the circle.\n\nSo, it is 3.14 x the amount of the radius x 2= the area of the circle.\n\nYou can do this in reverse as well, if you know the area but not the radius.
956315
The simplest way is to cut it into five slices, each with an arc of 72 degrees (or 2*pi/5 radians). You could probably also figure out a way to cut it into strips so that each strip has equal area, but that would be significantly more complicated.
865516
OK, I looked it up to find out what a pointed fifth dome is.\n\nI don't have time to figure it out, but I'd suggest starting with the equation of a circle centered at the origin.\n\nSince the pointed 5th is 4/5 of a full 90 degree arc, you're going to need to figure out what the x-value of the point that is .4 pi (4/5 of pi/2) would be.\n\nThen you would integrate to find the area under that curve.\n\nFinally you would get the volume by integrating in a cylindrical way around the vertical x value you determined above.\n\nI know that's a broad outline, but I hope it helps.
279982
You would show two circles cut into eights.  The first circle will have all 8/8 parts shaded.  The second circle will have 6/8 parts shaded. All together it would be 14/8.
471030
You will have a list of information, say the composition of x is 10%A, 33%B, 40%C and 17% D.\n\nConvert all these into a fraction of 360. (As a circle is 360 degrees)\n\nSo (10/100) x 360 = 36\nThis means that section A will have an angle of 36 degrees.\n\netc.\n\nDraw a circle then draw a single line from the centre to the edge. Use a protractor to measure 36% and draw a line.\n\nRepeat with all the other values until you have filled the circle.\n\nHope this helps.
975308
2.5 meters becomes the circumference of the circle when you form the rope into that shape.  The formula used for determining the diameter of a circle when the circumference is known is: d=c/pi\n\nFor your question, d=2.5/pi\nTherefore, d=0.796 m
634060
The length of one side of the rectangle can be related to the Circumference of the circle.\nTo get the perimeter of a circle, called the circumference of the circle, one simply has to multiply 2 times pi (about 3.14) times the radius of the particular circle. \nThe circumference of a circle can be calculated from its diameter using the formula:\nc = πd\nOr, substituting the radius for the diameter:\nc = 2πr\nWhere r is the radius and d is the diameter of the circle, and π (the Greek letter pi) is the constant 3.141 592 653 589 793...
711674
the circumference of a circle is the diameter * pi.\n\nor...\n\nC = d * 3.14
207955
u need more info than just the length, but here is something which might help u are speaking of ovals( called ellipses in math)\n\n\nwell the formula for them is\n\n\n(x^2)/a^2  +  (y^2)/b^2  =1\n\nwhere a and b are half of the major and minor axis , you only know 1 of these meassures, thats not enough sorry chap, wish i could help, but i think no one can, with only that info
1143102
Example - you'll need to apply it to your own endpoints.\n\nA circle is described on the line joining (-2,5)and(3,4) as diameter, find its equation:\n\nThe equation for a circle is:\n(x-h)^2 + (y-k)^2 = r^2 where (h,k) is the center and r is the radius\n\nIt is easiest to find the center first. it is the midpoint of the line and the slope is constant:\nh = x1-[(x1-x2)/2] = 3 - 5/2 = 1/2\nk = y1-[(y1-y2)/2] = 5 - 1/2 = 4.5\n\nNow, find the radius using the distance formula to find the distance between the center and the endpoint or by using a right triangle where dx and dy are the lengths of the legs. I prefer the latter, but they are pretty much the same:\ndx^2 + dy^2 = r^2\nr^2 = (5/2)^2 + (1/2)^2= 26/4 = 13/2\nBy substituing back into the equation for a circle:\n(x-.5)^2 + (y-4.5)^2 = (6.5)^2 = 42.25
292936
You cut at 1/4 of the distance from the center to the edge.  If you want it more exact, it's 0.2649 of the radius.  Steve is wrong, size of the cookie doesn't matter.\n\nIf you want the trig: the cut is a chord parallel to the horizontal diameter.  Draw radii to the ends of the chord, and an altitude from the center of the circle to the (center) of the chord.  For convenience let radius r=1.  Length of altitude = d.  Half the length of the chord = w.  And angle between altitude and radius = x (in radians). \n\nNow area of the sector is 2x/2pi*pi*r^2 = (so nice!) just x.  Area of the triangle is 1/2 base * height = d*w.  And we eventually want the value of d, distance from center to the cut.\n\nSo area of the slice = area of sector - area of triangle=\nx-dw=1/3*area of whole circle = 1/3*pi*r^2=pi/3\nSince d=cos(x) and w=sin(x), \nwe need to solve x-cos(x)*sin(x)=pi/3.\nUsing a graphing calculator, we get x=1.302662837 radians, for which cos(x)=d=0.2649320846.
914363
Find the center-radious form of the equation of the circle with center = (2,-6) and the tangent to the y-axis.\n\nIf tangent to the y - axis then the point (0, -6) is the point of contact (as tangent to circle _|_ radius at point of contact)\n\nTherefore radius = 2\n\nTherefore required circle is\n\n(x - 2)² + (y + 6)² = 2²
234891
I'm assuming that you are going to wrap the sheet to form a cone. \n\nTo simplify things, let x be the radius of the semicircle.\nThe circumfrence of the full circle is 2(pi)x, so the length of the semicircle arc is (pi)x. When you wrap the semicircle to form a cone, the base of the cone will have circumfrence of (pi)x, so its radius is x/2. The cone you get will have a sloping side of length x.\n\nThe volume of the cone is (pi)(r^2)h/3.\n\nThe height of the cone is third side of the triangle formed by the sloping side of the code (length x) and a radius of the base (x/2), so its length is sqrt(x^2 - (x/2)^2) = (x)sqrt(3)/2.\n\nSo the volume is ((pi)((x/2)^2)(x)sqrt(3)/2)/3 = \n\n((pi)((x^3)sqrt(3))/24 \n\nSubstituting x = 140mm  = 14 cm you have:\n\n((pi)((14^3)sqrt(3))/24 = 622.1 cc\n\n(Check arthmetic)
945543
A short element of the curve is dL=sqrt(dr^2+(r*dt)^2), r*dt elementary length of the arc with radius r and polar angle t (your theta), dr elementary increase of r for dt.\nThus dL=sqrt(r’^2+r^2)*dt.\nIf  r=a*(1-cost), then dL=a*sqrt((sint)^2+(1-cost)^2)=a*sqrt(2)*sqrt(1-cost)*dt. \nFortunately 1-cost=2*(sin(t/2))^2 or dL=2a*sin(t/2)*dt, L=-4a*cos(t/2) for t=0 until 2pi, thus L=-4*a*(-1-1)=8*a – Oh! check it poor kid!\nIf r=(sin(t/2))^2=0.5*(1-cost), then a=0.5 for t=0 until pi. It must be done likewise. Thus L=-4*0.5*(0-1)=2
418892
Since O is the center, this problem becomes fairly straightforward.  First, assuming <BOA = 94 degrees (not sure which of the four angles at O is 94 degrees, but say it's <BOA.  This means that the arc from B to A is also 94 degrees.  And since the chord from A to C goes through the center, it means it is a diameter.  This means that the arc from A to C is 180 degrees (half of the circle).  So that means that the arc from B to C has to be 86 degrees (180 - 94, because part of that arc from A to B is 94, the rest must add up to 180).  So now you have to use what your teacher told you about when the angle is on the circle.  Namely, that the angle on the circle (the inscribed angle) is half of the arc measure (intercepted arc).  So if the arc measure is 86 degrees, the angle must be 43 degrees.\n\nEdit: I just saw that it was <COD, not <BOA, but they are congruent because the are vertical angles, so nothing changes.
966696
Arc=r.theta=8*pi/8=pi