







Seven tangent circles 
20180423 

Domenick pose la question : How to calculate the circumscribed and inscribed circles formed by seven .019685 diameter circles arranged in a circle with all seven circles tangent to each other? Penny Nom lui répond. 





Two tangent circles 
20161127 

mikee pose la question : find the equation of a circle tangent to the circle x2+y2=4
and with the center at (0,5) Penny Nom lui répond. 





Two circles that touch each other externally 
20140408 

Ameya pose la question : Two circles of radii a and b (a > b) touch each other externally. ST is a common tangent touching the circles at S and T respectively, then ST^2 is equal to Chris Fisher lui répond. 





Four tangent circles 
20131009 

Nilesh pose la question : Four circular cardboard pieces, each of radius 7cm are placed in such a way that each piece touches two other pieces. How to find the area of the space enclosed by the four pieces?
Please let me know. Robert Dawson lui répond. 





Four tangent circles 
20121004 

renu pose la question : inside of a circle K of radius length measure R,three circular discs A,Band C each of radius r are placed so that each touches the other two and K . express R in terms of r. in the space between K, A and B , another circular disc D is placed which just touches K, A and B. if the radius is s, show that (6+root3)s=(2+root3)r Penny Nom lui répond. 





One central circle and three tangent circles 
20111016 

Margaret pose la question : You have one central circle and three or more circles tangent to the outside of the circle of varying radii. You know the x,y coordinates of the centers of the other circles. If you now remove that central circle (and pretend you never knew where it was), can you calculate its center in x,y coordinates? Chris Fisher lui répond. 





Three tangent circles 
20110821 

maribie pose la question : three discs are tangent externally distances between their centers are 23cm, 15cm, and 20cm. find their radii.t Penny Nom lui répond. 





Three tangent circles 
20110819 

hanniel pose la question : two coin are tangent to a third coin internally and are tangent to each other
externally. The distance between their centers are 14 mm, 17mm, and 5mm.
find their radii Penny Nom lui répond. 





Three tangent circles 
20110501 

mark pose la question : Three circles of radii 24 cm, 32 cm, and 42 cm are externally tangent to each
other (each is tangent to the other two). Draw a diagram and using the Law of
Cosines find the largest angle of the triangle formed by joining their centres. Penny Nom lui répond. 





Two tangent circles 
20110209 

xhesika(jessica) pose la question : Two circles of radius 10 are tangent to each other.A tangent is drawn
from the centre of one of the circles to the second circle.To the nearest
integer find the area of the shaded region. Penny Nom lui répond. 





Three circles 
20091002 

Brandon pose la question : There is a quarter circle with a radius of 1. along one eged of it,
there is a semicircl with a diameter of 1, and its center is on the
drawn line. there is another semicircle again with the center on the
other drawn line, and this one has an unknown diameter of X. both
circles are internally tangent, and are tangent to each other. Find X. Robert Dawson and Chris Fisher lui répond. 





Two tangent circles 
20090123 

Murtaza pose la question : Two circles touch externally at T. A chord of the first circle XY is produced and touches the other at Z. The chord ZT of the second circle, when produced, cuts the first circle at W. Prove that angle XTW = angle YTZ. Robert Dawson and Chris Fisher lui répond. 





Two tangent circles 
20080822 

Michele pose la question : A circle of radius 2 is externally tangent to a circle of radius 8,
How do you find the length of their common tangent. Penny Nom lui répond. 





Area of triangle formed by three tangent circles 
20080731 

brian pose la question : Three circles with radii 3,4 and 5 touch each other. The circles are tangent to each other. What is the area of the triangle formed by the centers of the circles? Stephen La Rocque lui répond. 





Four tangent circles 
20051206 

Ananth pose la question :
I have one bigger circle A with radius 15.
Inside this bigger circle i have another circle B with radius 3 which touch this bigger circle. Have another circle C with radius 4 which touches A and B. I would like to draw a biggest circle which touches A,B and C.
Chris Fisher lui répond. 

