Answer
$d \approx 5.62$
Work Step by Step
$$\eqalign{
& {\text{Let the points: }}\underbrace {\left( {2,0.5} \right)}_{\left( {{r_1},{\theta _1}} \right)}{\text{ and }}\underbrace {\left( {7,1.2} \right)}_{\left( {{r_2},{\theta _2}} \right)} \cr
& {\text{Apply }}d = \sqrt {r_1^2 + r_2^2 - 2{r_1}{r_2}\cos \left( {{\theta _1} - {\theta _2}} \right)} \cr
& d = \sqrt {{{\left( 2 \right)}^2} + {{\left( 7 \right)}^2} - 2\left( 2 \right)\left( 7 \right)\cos \left( {0.5 - 1.2} \right)} \cr
& {\text{Simplifying}} \cr
& d = \sqrt {4 + 49 - 28\cos \left( { - 0.7} \right)} \cr
& d \approx \sqrt {53 - 21.4156} \cr
& d \approx \sqrt {31.584} \cr
& d \approx 5.62 \cr} $$
