Does anyone know how to do this? i’ve been trying to figure this out for the past hour and i can’t

Two sides of a triangle mesure 20cm and 30cm. what is the measure of the third side

Which math sentence can be used to determine if the triangle is a right triangle?

Liz is shipping a package to her friend. the maximum weight of a medium flat-rate box is 20 pounds, including the box which weighs 6 ounces. write and solve an inequality to describe the possible weight ,w, of the contents that liz will ship to her friend if she must use a medium flat-rate box.