Trig question -- if you can! i have to write y = r cos(θ + r) and z = r sin(θ + r) in terms of y, z, and r. i'm not really sure how to do this, so would you mind showing work so i can learn the steps properly? (teacher hasn't taught this super well, haha)

Asquare concert stage in the center of a fairground has an area of 2 2 4 12 9 ft . x x ? ? the dimensions of the stage have the form cx ? d, where c and d are whole numbers. find an expression for the perimeter of the stage. what is the perimeter when x ? 2 ft?