3D geometry on radial coordinates?

All angles are defined in degrees.

We represent points as ( r, $\theta_1$ , $\theta_2$ ).

r stands for the distance of the point away from the origin.

$\theta_1$ stands for the horizontal angle away from the horizontal line going east from the origin, going clockwise. $0 \leq \theta_1 \leq 360$ .

$\theta_2$ stands for the vertical angle away from the horizontal line going east from the origin, going anti-clockwise. $0 \leq \theta_2 \leq 360$ .

An example of what this means is that (4, 60, 30) translates to (3, $\sqrt{3}$ , 2) in the Cartesian coordinates.

What is the approximate distance of (8,59,70) from (5,3,79)? (to 3 significant figures)