State a number whose square root is neither negative nor positive​

Aman is 6 feet 3 inches tall. the top of his shadow touches a fire hydrant that is 13 feet 6 inches away. what is the angle of elevation from the base of the fire hydrant to the top of the man's head?

An airplane travels at an unknown elevation before it descends 3 miles to an elevation of 15 miles. find the elevation of the plane before its descen.

Me i'm timed ! a. -2 to 1 b. -1.5 to 0.5c. 0 to 1d. 0.5 to 1.5