Which statement is false ? 1. every integer is also a real number , 2. no irrational number is rational , 3. every integer is also an irrational number , 4. every irrational number is also a real number ?

From the top of a tree a bird looks down on a field mouse at an angle of depression of 50°. if the field mouse is 40 meters from the base of the tree, find the vertical distance from the ground to the bird's eyes.