# circle

1. ### 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. ### 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...

4. ### 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. ### 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. ### Triangle in a cyrcle

Does anyone know how to solve this? It has no information, just the answer is given, which is 72deg.
7. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### 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. ### Circle Geometry Question Help

Need help finding BDC. Thank you.
19. ### Points on a circle

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