If the center distance of two circles with radius of 2 and 5 is 7, the position relationship between the two circles is______ ．

If the center distance of two circles with radius of 2 and 5 is 7, the position relationship between the two circles is______ ．

∵ r = 5, r = 2, ∵ R + r = 2 + 5 = 7, ∵ d = 7, ∵ R + r = D, ∵ the position relation of two circles is circumscribed

The radii of circle O1 and circle O2 are 2 and 5 respectively. When the distance between the two circles is 2.5, what is the position relationship between them?

It's internal,

It is known that the radius r of O 1 is 30 O 2, the radius R is 4, and the distance between the centers of two circles is 1

Analysis:
It is known that r = 3, r = 4 and d = 1
Then d = r-r
Therefore, we can see that the position relationship of two circles is inscribed

Given that the radius of circle O1 and circle O2 are R respectively, the center distance of circle O1 is d = 5, r = 2 (1) circle O1, the circumscribed of circle O2 is R (2) r = 7, what is the position relationship between circle O1 and circle O2
(3) What is the positional relationship between circle O1 and circle O2?

1) Two circumscribed circles, R + r = D,
That is, 2 + r = 5,
The solution is r = 3
2) When r = 7, R-R = 7-2 = 5 = D,
So the two circles are inscribed
3) When r = 4, R-R

The center of two equal circles is o 1 O 2, the circle O 1 passes through O 2, and the two circles intersect at P Q. given o 1 O 2 = 6cm, what is the intersection area?

Solution: connect PQ and O1O2, cross a, connect po1, PO2, QO2 PQ.PO2=O1O2=PO1 Then PA = √ (o2p & # 178; - O2A & # 178;) = 3 √ 3, PQ = 2PA = 6 √ 3. S sector o2po1q = 120 π * 6 & # 178;) / 360 = 1

It is known that circle O1 and circle O2 are tangent to point P, O1O2 = 10, and the radius of one circle is 15. Find the radius of the other circle

2.5 or 17.5 cut in and cut out

On the same plane, if the radii of ⊙ O1 and ⊙ O2 are 2 and 1, respectively, and O1O2 = 5, then the circle with radius of 9 and tangent to ⊙ O1 and ⊙ O2 has______ One

∵ O1O2 = 5 ＞ 2 + 1, ∵ O1O2 = 5, ⊙ O1, ⊙ O2 have radii of 2 and 1, respectively, ∵ radius of 9, there are two circles which are inscribed with them at the same time, ∵ there is one circle which is circumscribed with ⊙ O1, ⊙ O2, there is one circle which is inscribed with ⊙ O1, ⊙ O2, and there are two circles which are both circumscribed

If ⊙ O1 and ⊙ O2 are known to be circumscribed, and the radii are 2 and 1 respectively, then the circle with radius 4 on the plane and tangent to ⊙ O1 and ⊙ O2 has ()
A,2 B,4 C,5 D,6

There are 6 choices in D, among which
There are two and ⊙ O1, ⊙ O2, one inscribed and one circumscribed;
Two and ⊙ O1, ⊙ O2 are circumscribed;
There are two and ⊙ O1, ⊙ O2 are both inscribed

The radii of circle O1 and circle O2 are 2 and 3 respectively, and circle O1 and circle O2 are circumscribed
1. How many circles are tangent to circle O1 and circle O2 with radius of 5 in the plane?
2. How many circles are tangent to circle O1 and circle O2 with radius of 6 in the plane?
3. How many circles are tangent to circle O1 and circle O2 with radius of 4 in the plane?

Let this circle be o (let's say better) 1. O and garden one, garden two inscribed O and garden one circumscribed O and garden two circumscribed O and garden two circumscribed O and garden one circumscribed O and garden two circumscribed (two cases) there are five 2. O and garden one, garden two circumscribed (two cases) O and garden one circumscribed O and garden two circumscribed O and garden two circumscribed O and garden one circumscribed O and garden two circumscribed o

If the distance between the centers of two circles d = 6 and the radii of two circles are two of the equations x ^ 2-5x + 1 = 0, then the position relationship between the two circles is?

∵ the radii of the two circles are two of the equation x ^ 2-5x + 1 = 0,
The sum of the radii of the two circles is 5,
And the center distance of two circles d = 6,
Then the two circles are separated