CPM Homework Help : PC Problem 4-129

Challenge: A tree is growing at a rate of $t$ feet per year. Rocky finds the point where he can stand just in the shadow of the tree. Rocky is $6$ feet tall and has stopped growing. The tree is currently $20$ feet tall. Find Rocky’s distance from the tree as a function of $t$ and $θ$ .

Right triangle, vertical leg represents tree labeled 20 +, angle opposite vertical leg labeled theta, vertical segment between vertical leg and it's opposite angle, represents person labeled 6, divides the horizontal leg into 2 sections, section between vertical leg & vertical segment labeled, d.

Hint:

Let the distance from the tree to Rocky be d and the distance from Rocky
to the tip of his shadow be x. Write two tan equations and solve.