Circle A has a center at #(1 ,4 )# and a radius of #2 #. Circle B has a center at #(9 ,3 )# and a radius of #1 #. Do the circles overlap? If not what is the smallest distance between them?
1 Answer
Explanation:
If the distance between centres is less than the sum of the radii then they overlap.
Let point 1 be
Let point 2 be
Let the distance between centres be
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Using Pythagoras
This is approximately
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The sum of the radii is
So if the sum of the radii is 3 and the distance between centres is very close to 8