How can i put 2 wholes and 4 over 25 in a percent

2 4/25

multiply the whole number(2) by the denominator(25) then add four to the answer and then out the answer over 25. so it should look like 54/25 then divide the top number by the denominator and you get 2.16 which if you move the decimal back two places you get 216%

12=2s
s=6

if the shape is a square, then all sides must be the same so the top and bottom would just be 2s, which would be equal to 12 and divide that by 2 to get your answer of what s is.