What side lengths form a right triangle?

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)

Of the 304 people who attended a school play, 5/8 were students. how many of the people who attended were students.

Given the numbers c = –3 and d = 4, which statement is true? a. |–c| = 3 and |–d| = –4 b. |–c| = 3 and –|d| = –4 c. –|c| = –4 and –|d| = 3 d. |–c| = 3 and –|d| = 4