Final answer:
The program should convert a user-entered length in centimeters to inches, unless the value is negative, in which case it should report the entry as invalid. The conversion uses a conversion factor of 2.54 centimeters per inch.
Step-by-step explanation:
The question asks to write a program that converts a length from centimeters to inches, with a check for negative values. The program should prompt the user to enter a length in centimeters. If the user enters a positive value, the program will convert that length into inches using the conversion factor that 1 inch is equal to 2.54 centimeters. If the entered length is negative, the program will inform the user that the entry is invalid.
To perform the conversion, you would divide the number of centimeters by 2.54 (since there are 2.54 centimeters in one inch). A simple example in a programming language like Python could look like this:
length_in_cm = float(input('Enter length in centimeters: '))
if length_in_cm < 0:
print('The entry is invalid.')
else:
length_in_inches = length_in_cm / 2.54
print(f'{length_in_cm} cm is equal to {length_in_inches} inches')