A trapezoid has an area of 145.5 square miles. One base is 19.1 miles long. The height measures 10 miles. What is the length of the other base?
miles
Area of a trapezoid = (1/2) (height) ( sum of parallel base lengths)
So
145.5 = (1/2) (10) (19.1 + other base length)
145.5 = 5 (19.1 + other base length) divide both sides by 5
29.1 = 19.1 + other base length subtract 19.1 from both sides
10 miles = other base length