Select all irrational numbers.

The answers are A and D.
The numbers that you cannot simplify without having a radical in the answer are irrational numbers. 

√(4/16) = 1/4 or -1/4, rational number
√(9/16) = 3/4 or -3/4, rational number
√(9/4) = 3/2 or -3/2, rational number

√(3/16) = √(3)/4, NOT a rational number, cannot remove radical
√(3/4) = √(3)/2, NOT a rational number, cannot remove radical 

Its equal to d=7.07in

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