The area of triangle is equal to 1/2 multiplied by base and height. In this case, height is equal to b - 3 and area is equal to 19 b. thus the equation is 19 b = 0.5 (b-3 ) b b is then equal to 41 units. h is b - 3 equal to 38 units.
Make two equations from the information. Then graph them and see where they intersect. The answer is 62 miles. Plug 62 back into both equations and they should both be the same number.