How do you find missing sides of a triangle

Aparallelogram has an area of 216.24 cm2 and a height of 15.9 cm. how long is the base of the parallelogram? enter your answer as a decimal in the box. cm

Each of the walls of a room with square dimensions has been built with two pieces of sheetrock, a smaller one and a larger one. the length of all the smaller ones is the same and is stored in the variable small. similarly, the length of all the larger ones is the same and is stored in the variable large. write a single expression whose value is the total area of this room. do not use any method invocations.

Is a positive integer raised to a negative power always positive