The formula for the area of a triangle is a = __1 2bh, in which b represents the length of the base and h represents the height. if a triangle has an area of 192 mm2 and the height is 12 mm, what is the measure of the base?

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?