Find the missing side round to the nearest tenth

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

Atotal of 766 tickets were sold for the school play. they were either adult tickets or student tickets. there were 66 more student tickets sold than adult tickets. how many adult tickets were sold?

If a runner who runs at a constant speed of p miles per hour runs a mile in exactly p minutes what is the integer closest to the value p