Multiplying Polar Coordinates

Algebra Level 1

What do we obtain when we multiply the polar coordinates:

$( r_1 , \theta _1 ) \times ( r_2 , \theta _2 ) ?$

( r_1 \times r_2 , \theta_1 \times \theta _2 )

( r_1 + r_2 , \theta_1 \times \theta _2 )

( r_1 + r_2 , \theta_1 + \theta _2 )

( r_1 \times r_2 , \theta_1 + \theta _2 )