$\"\"$

The pair of points $\"\"$ and $\"\"$ .

The polar distance formula is $\"\"$ .

Substitute $\"\"$ and $\"\"$ in the distance formula.

$\"\"$

Trignometry property : $\"\"$ .

$\"\"$

Substitute above value in distance formula.

$\"\"$

The distance between each pair of point is $\"\"$ .

$\"\"$

The distance between each pair of point is $\"\"$ is $\"\"$ .