+0  
 
0
42
1
avatar

(1) A circle centered at P with radius 10 and a circle centered at Q with radius 8 are externally tangent.   Find PQ.

 

(2) How many common external tangents do two circles have?

 Sep 17, 2021
 #1
avatar
0

 

(1) A circle centered at P with radius 10 and a circle centered at Q with radius 8 are externally tangent.   Find PQ.    

 

If you'll draw this, you'll easily see that it's the sum of the two radii, namely 10 + 8 = 18  

 

(2) How many common external tangents do two circles have?    

 

You didn't say if this is specifically in reference to the two circles in (1).  Well, anyway: 

 

If two circles are overlapping, they can have 2 common tangents.  

If two circles are externally tangent, they can have 3 common tangents.  

If two circles are some distance apart, they can have 4 common tangents. 

.

 Sep 17, 2021

20 Online Users

avatar
avatar
avatar