circle

  1. R

    3.14 vs. 3.141.../irrational pi for a circle

    I realize math can be used for abstraction... Would using irrational pi for a circle other than 3.14 make the circle more eliptical? Why use the irrational number for a circle, instead of 3.14, if the irrational size for a circle cannot even exist in reality? why use it for a circle?
  2. A

    Condition for a chord of contact to subtend a right angle at the center.

    This is a question form SL Loney's The Elements of Coordinate Geometry : Find the condition that the chord of contact of tangents from the point (x' , y') to the circle x^2 + y^2 = a^2 should subtend a right angle at the center. Now what I can propose is, the equation to the chord of...
  3. S

    How do I solve cos(X-20degrees)= 1/2 ?

    This is the question. Please help!
  4. I

    Internally Tangent Circle Problem Help

    Prove: If two circles are tangent internally at point P and the chords PA and (chord) PB of the larger circle intersect the smaller circle at points C and D respectively, then (chord) AB is parallel to (chord) CD.
  5. R

    Determining Coordinates of Two points On a Circle

    Assuming you have a circle with a radius of 2 with a line drawn exactly 1 unit away. What are the coordinates of the two points the line intersects. And how do I solve for it. The picture explains it well
  6. B

    Triangle in a cyrcle

    Does anyone know how to solve this? It has no information, just the answer is given, which is 72deg.
  7. P

    Find the equations of the common tangents to parabola and circle

    Hi everyone! I'm having some troubles resolving one last point of my weekly sheet.The text says: "Find the equations of the common tangents to the parabola y^2=15*x and the circle x^2+y^2=16." I tried the approach of the discriminant and also one using the distance from a line but both didn't...
  8. N

    Euclidean Circle Geometry

    I need to calculate the angles A1, O1 and B2. In the diagram I understand that DEF is a tangent to the circle that goes through A, B, C and E. O is the centre. BC=CE, AEC = 105, CEF = 40.
  9. N

    Euclidean Circle Geometry

    In the diagram below, XY is a chord of the circle that goes through X, Y and Z. WZ is a tangent to the circle. XZ = YZ XZW = x-30 degrees XZY = 4x I want to calculate the value of x in order to move on to the next steps. Any advice or tips on where to start?
  10. N

    Euclidean Circle Geometry. Calculating the Radius

    In the diagram below, DE is a chord of the circle that goes through c,d and e. A is the center of the circle. The perpendicular line from centre A intersects DE at B and the circle at C, DE=100cm BC= 10cm AB=X I need to calculate the length of AB / x. Basically i need to calculate the...
  11. K

    Find circle with 3 points

    (2,1), (6,5), (0,-5) After several pages of calculations, I got nothing. I made an equation for each point, and since they were each equal to r^2, I set them equal to each other and solved for h in terms of k. You can do this three unique ways, and I got three unique values for h in terms...
  12. X

    area of region outside the circle by r =1 and inside the cardroid r = 1- sin (theta)

    Find the area of region outside the circle by r =1 and inside the cardroid r = 1- sin (theta) Here's my working. but the ans given is 2 + (pi/4) unit ... Why am i wrong ?
  13. H

    How can measure of a minor arc is equal to measure of its central angle in a circle?

    How can measure of a minor arc is equal to measure of its central angle in a circle?
  14. M

    circle questions

    Hi, sorry this is my first time on this forum, hope these questions are suitable enough to be posted here, they're suppose to be questions manageable for a 12-year-old which makes me even more worried about my math skills nowadays... anyway this is the first question: and here's the second...
  15. P

    Circle

    Someone could resolve this matter of Circle? Number 1 ok : d=√(r2-r+1). Number 2 ok : r =1/2 Number 3: I found Area of the circle's sector is A= cos-1(d/2)=cos-1 (sqrt3/4)? and then? Area of the sector's segment= sqrt39/16?
  16. R

    Finding the tangent to a circle equation given the circle equation

    Hi guys, first time poster here! There' this equation I don't quite understand. I'm given the following question: The tangent line to the curve (x^2) (y^2) − (2x^2) + (y^2) = 0 at the point (1, 1) is=? Not quite sure how to deal with the circle arranged that way? I really need to understand...
  17. E

    Calculating the height of a circle segment

    Hey guys, I'm helping my father with some calculations for building a steam engine. I need to calculate the height of a circle segment i know the area of and also knowing the radius. I got as far as finding the following formula: Area of segment = (((Ɵ/360) * π – (sin(Ɵ)/2)) x r² I understand...
  18. X

    Circle Geometry Question Help

    Need help finding BDC. Thank you.
  19. J

    Points on a circle

    I need help solving this one. Dont even know where to start. Thanks, Jackson
  20. M

    motion in a circle

    hi i cant solve this a particle of mass 8kg is describing a circle, with constant speed v, on a smooth horizontal table. it is connected by a light inextensible string of length 3m to a point which is 1m vertically above the centre of the circle. (i) show that the particle will remain in...