# circles

1. ### Mohr Circles ?? how to creat a tangent for a set of Circle equations ??

hi guys i'm studying civil engineering , and part of it we study Mohr Circles of stress analysis But we still do it Graphically and that is not off course as accurate as you want, anyway i did my part summarizing it . So first let explain to you what we do here , we do Lab experiments...
2. ### Equation of circles help?

The centre of two circles lie on the line x+y-7=0 Both circles touch the x - axis and contain the point (6,2), find the equations of the two circles that satisfy these conditions.
3. ### Two circles intersecting each other...

Two circles intersect each other at A and B as shown in the figure. The common chord AB is produced to meet a common tangent PQ to the circles at D. Prove that DP=DQ.
4. ### Circles

Okay, I have a question on an exam paper that I just can't seem to do. :( Well okay. It's a circle. It's been cut. So we have a triangle and a sector. The radius is 4cm. The sector area is Acm^2 and the perimeter is Xcm and X = 3A. Now. I have to show with that information that the...
5. ### circles touching internally/area...

Two circles touch internally. The sum of their areas is 116π sq. cm and distance between their centres is 6cm. Find the radii of the circles.
6. ### Question about tangent lines to circles...

I'm using the Sullivan Precalculus 7th Edition book for self-study. I actually have a background all the way through integral calculus, but that was years ago and I'm trying to relearn much of what I've forgotten. In particular, one of the early problems has me completely stumped and I've...
7. ### 4th Six Weeks Project Help (Triangles & Circles)

Okay, so I have a project forth 4th six weeks of school, I basically have it done and all. However I have one problem, I am not sure which to label what. I have a circle, with a triangle inside the circle, and inside the circle I have another circle that touches all sides of the triangle...

9. ### circles and calculus

P_1, P_2, P_3, P_4 are points (cp_1, \frac{c}{p_1}) (cp_2, \frac{c}{p_2}) (cp_3, \frac{c}{p_3}) (cp_4, \frac{c}{p_4}) on the rectangular hyperbola xy = c^2. By showing that the chord P_1P_2 has the equation, x + t_1t_2y = c(t_1 + t_2), and given that the circle x^2 + y^2 = R^2...

11. ### Triangle inscribed in two circles...

I need help with the set up of this problem... Two circles meet at points P & Q. Let segment AP and segment BP be diameters of the circles. Show that segment AB passes through the other intersection Q. See attached file. Any help would be greatly appreciated...
12. ### PSAT questions: Probablility & Area of Circles

I am surprised to see these problems on the PSATs. I can't imagine what the SATS will be like. I did not understand problems 15 and 18. They qualify as 'Hard' questions. Do you think so? I ransacked my brain, trying to find a solution but my efforts were to no avail. (Pardon the messy...
13. ### Circles

In the figure, two circles cut at A and B. P and Q are the centres of the circles. If <APB=90 and <AQB=60 then find the area of the shaded portion if AP=4cm.
14. ### circles

Two circles are drawn in a 12-inch by 14-inch rectangle. Each circle has a diameter of 6 inches. If the circles do not extend beyond the rectangular region, what is the greatest possible distance between the centers of the two circles?
15. ### Coordinate geometry: tangent to two circles

consider two circles of radius r1 and r2, centres (x1, y1) and (x2, y2). there are two lines that are tangents to BOTH these circles that DON' T cross the line joining the centres of the circles (clearly there are two more that do cross the line joining the centres of the circles). Anyone know...
16. ### find the area shaded by the circles

find the area shared by the circles r=2cos(theta) and r=2sin(theta). i know the general formula for finding the area, but i don't know which is the outside one, and which is the inside circle. but i've tried both ways and am still not getting the right answer. so let's just say i'll try it...
17. ### Two circles and a square

Please solve this problem. Thanks. Two distinct circles and a square lie in the plane. What is the maximum number of points of intersection of two or more of these three figures?
18. ### Disjoint Circles

How can prove that? Let C be a collection of disjoint circles in the plane. Show that there is a line that passes through the origin and not any of these tangent circles. THANKS!
19. ### three circles inscribed in a big circle

hello ! help me to solve this problem, please!! its really hard for me ! thank you so much and God bless you richly !(Wink) Three circles A,B and C are tangent externally to each other and each tangent internally to a larger circle having a radius of 10 cm. Radius of circle A is 5 cm. a)...
20. ### Ratio of area of two circles

A circle with center O intersects another circle with center P at points C and D. if angle COD = 30 and angle CPD = 60, what is the ratio of the area of the circle with center O to the area of the circle with center P? Answer= 1: (2-√3) Can someone paint me a picture of this because I don't...