Wich expression equivalent to

Atriangle has sides with lengths of 10 yards, 13 yards, and 18 yards. is it a right triangle?

What is the length of an with endpoints a 3,2 and b 8,14

Noor brought 21 sheets of stickers. she gave 1/3 of a sheet to each of the 45 students at recess. she wants to give teachers 1 1/2 sheets each.