I put B but it said it was wrong???

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

In the field of thermodynamics, rankine is the unit used to measure temperature. one can convert temperature from celsius into rankine using the formula , what is the temperature in celsius corresponding to r degrees rankine? a. 9/5(c - 273) b. 9/5(c + 273) c. 5/9( c - 273) d. 5/9( c + 273)

The given diagram shows the parts of a right triangle with an altitude to the hypotenuse. using the two given  measures, find the other four.