Area of triangle 4cm, 5cm and 3cm

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)

Two angles are complementary. the larger angle is 36 more than the smaller angle. what is the measure of the larger angle?

If f(x)=x+7 and g(x)=1/x what is (fog)(x)