4a^2+b^2−c^2+4ab Help me find the answer plz

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

Which table shows a proportional relationship between miles traveled and gas used?

Awater tank holds 18000 gallons. how long will it take for the water level to reach 6000 gallons if the water is used at anaverage rate of 450 gallons per day