Jacy anchors a retractable leash to a tree and attaches the leash to her dog's collar. When the dog fully extends the leash, the angle between the leash and the tree is 84º.
Her neighbors yard is 18 ft away.

A. The dog can go [insert answer] ft into the yard.

B. She wants to make sure it can’t go into the yard how high must she anchor the leash ?