$\"\"$

The area of the circle is $\"\"$ .

The area of a circle formula is $\"\"$

$\"\"$ (Substitute 87 for A and 3.14 for $\"\"$ )

$\"\"$ (Divide each side by 3.14)

$\"\"$ (Cancel common terms)

$\"\"$ (Divide: $\"\"$ ) $\"\"$

$\"\"$ (Take square root of each side)

$\"\"$ (Cancel square and root)

$\"\"$ (Use a calculator) $\"\"$

The diameter of a circle is twice to its radius, $\"\"$ .

$\"\"$ (Multiply: $\"\"$ )

$\"\"$ ft (Rounded to nearest foot) \ \

$\"\"$

The diameter of the circle is 11 ft.