When a number is a multiple of another, the gcf of the numbers is the greater of the numbers. is this always, sometimes, or never true

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

Someone answer asap for ! the boiling point of water at an elevation of 0 feet is 212 degrees fahrenheit (°f). for every 1,000 feet of increase in elevation, the boiling point of water decreases by about 2°f. which of the following represents this relationship if b is the boiling point of water at an elevation of e thousand feet? a. e = 2b - 212 b. b = 2e - 212 c. e = -2b + 212 d. b = -2e + 212

See attachment below and find the equivalent of tan(∠qsr)