Is there anyone who can give me the steps for solving this one?

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

How can you construct perpendicular lines and prove theorems about perpendicular lines

Tom is the deli manager at a grocery store. he needs to schedule employee to staff the deli department for no more that 260 person-hours per week. tom has one part-time employee who works 20 person-hours per week. each full-time employee works 40 person-hours per week. write and inequality to determine n, the number of full-time employees tom may schedule, so that his employees work on more than 260 person-hours per week. graph the solution set to this inequality.