Question 852149
<pre>
{{{drawing(300,300,-13,13,-13,13,circle(0,0,12),circle(0,0,11),
locate(5.5,0,12), locate(2.7,5,13), 
red(line(0,0,9,7.937253933)),green(line(0,0,11))) 

 )}}}

The green line is the radius of the swimming pool, the INNER circle.
Since its diameter is 24 yards, its radius is 12 yards.
Its area is gotten by using A = <font face="symbol">p</font>r<sup>2</sup>.
A = 3.14×12<sup>2</sup> = 452.16 square yards.

Since the walk around the swimming pool is 1 yd. wide, the radius of
the OUTER circle has a radius of 1 yd. more than the radius of the inner 
circle, or 13 yd. Its area is also gotten by using A = <font face="symbol">p</font>r<sup>2</sup>.
A = 3.14×13<sup>2</sup> = 530.66 square yards.

Area of walk = Area of OUTER circle MINUS Area of INNER circle:

Answer: 530.66 sq. yd. - 452.16 = 78.5 square yards. 

Edwin</pre>