SOLUTION: the circle centered at B is internally tangent to the circle centered at A. The smaller circle passes through the center of the larger circle and the length of AB is 5units. If th

Algebra ->  Circles -> SOLUTION: the circle centered at B is internally tangent to the circle centered at A. The smaller circle passes through the center of the larger circle and the length of AB is 5units. If th      Log On


   



Question 466105: the circle centered at B is internally tangent to the circle centered at A. The smaller circle passes through the center of the larger circle and the length of AB
is 5units. If the smaller circle IS REMOVED FROM THE LARGER CIRCLE, how much of the area,in square units, of the larger circle will remain?

Answer by Edwin McCravy(20064) About Me  (Show Source):
You can put this solution on YOUR website!


The area of the larger circle is found with formula:

A = pr²

The radius of the larger circle is 10 units,

so its area is

A = p(10)² = p*100 = 100p square units.

----

The area of the smaller circle is also found with formula 

A = pr²

The radius of the smaller circle is 5 units.

so its area is

A = p(5)² = p*15 = 25p square units.

----

Therefore when we remove the small circle, the area that's left is

 
100p - 25p square units, or

(100-25)p square units or

75p square units or approximately 235.6 square units.

Edwin