Which could be the lengths of the sides of a right triangle?

Use set buikder notation to represent the following set: {, -2, -1, 0}

The parabola x= √y-9 opens: a.)up b.)down c.)right d.)left

Afamily has five members. a mom, a dad, two sisters, & a brother. the family lines up single file. what is the probabillity that the mom is at the front of the line