$\"\"$

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

Height of the parallelogram is 20 m. and $\"\"$

Area of the parallelogram is $\"\"$

$\"\"$

$\"\"$ (Substitute 300 for A and 20 for h) $\"\"$

$\"\"$ (Divide each side by 20)

$\"\"$ (Cancel common terms)

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

The unknown measure of the parallelogram b is $\"\"$ .