Please help me . needs to be done asap

Me because some of question i don’t understand

Find the roots of the equation below. x^2 - 6 + 9 = 0

Astick 2 m long is placed vertically at point b. the top of the stick is in line with the top of a tree as seen from point a, which is 3 m from the stick and 30 m from the tree. how tall is the tree?