What is the measure of BC?

How do i start to solve? would appreciate a walk-thru! a bird sitting 16ft above the ground in an apple tree dislodges an apple. after how many seconds does the apple land on the ground? (assuming that no branches will interfere with it's fall)

What is the effect on the graph of the function f(x) = x2 when f(x) is changed to f(x) − 4?

On ryan's last social studies test there were two types of questions true/false worth 3 points each and multiple choice questions worth 4 points each