Which fraction expresses 36/80 in lowest terms? . . a. 9/20. . . b. 18/40. . . c. 4/5. . . d. 18/20. .

Find the largest number that can divided both the numerator, 36, and denominator, 80, of the given fraction. This number should be 4. Doing the operation gives us the answer of 9/20. Thus, the answer is letter A. 9/20. 

You have 2 sides that are 2 cms and you have 6 sides that are 1/2 cm and you have 4 sides that are 1 cm. the smallest sides are 1/2 the medium sized sides are 1 and the smallest are 1/2. so to find the perimeter you have to add them all up together so your answer will be 11 cm's