Can someone explain how to do this? i don't understand.

Which set of side lengths form a right side? a) 3ft,6ft,5ft b)50 in,48in,14in c)53m,48m,24m d)8cm,17cm,14cm

Two poles, ab and ed, are fixed to the ground with the of ropes ac and ec, as shown: what is the approximate distance, in feet, between the two poles? 6.93 feet 8.66 feet 12.32 feet 15.59 feet

Aculinary club earns $1360 from a dinner service. they sold 45 adult meals and 80 student meals. an adult meal costs twice as much as a student meal. what is the cost of an adult meal?