Pyramid with a rectangular base 6 cm and 8 cm, lateral face makes an angle of 30 degrees with the base. What is the altitude of the pyramid?
since the base is not square, the base angles on unequal sides cannot be the same. So, which side(s) are we talking about?
Anyway, once you have decided on the side to pick, the height is
s tan30 = s/√3
where s is the length of the base side adjacent to the sloping face.