$\"\"$

The angle of triangle $\"\"$ and its side is $\"\"$ .

If sketch the two triangle then necessary conditions: $\"\"$ is acute, $\"\"$ .

$\"\"$ (Write condition)

$\"\"$ (Substitute $\"\"$ )

$\"\"$ (Divide each term by b)

$\"\"$ (Write reciprocal form)

$\"\"$ (Multiply each term by 10)

$\"\"$ (Rewrite form) $\"\"$

The solution is $\"\"$ .