I need some translators pls (1 Viewer)

[HyperComplexxx]

i dont get what it means by PC is inclined to horizontal at an angle whose tangent is

 

[funnytomato]

let's call the foot of perpendicular of C on the extension of AB as point Q, so angle CQP=90 degrees

Hint consider the angles in triangle CBQ , then the rest of it would be quite obvious