15. (1 point) 25 ft. The length L of a long wall is to be approximated. The angle 9, as shown in the diagram (not to scale), is measured to be 47, accurate to within 0.1. Assume that the triangle formed is a right triangle. a) What is the measured length of the wall? feet b) Estimate an upper bound for the propagated error using a linear approximation. feet 0) What is an upper bound for the percent error