the solution at the right-hand side is what I want to explain at first I used the 5 to multiply the numbers above that is I used to 5 how to multiply 19.2 and that give me a value of 960 .Then , I used the 9 that is the number after the decimal point in 29.5 to multiply the 19.2 and it gave me 1728 then I use the 2 in 29.5 to multiply 19.2 and that gave me 384 . So ,when I add all numbers together it gave me 560 6.40
NB please at the right hand side I didn't put the Zero in the blank spaces . So, that's what I did at the left hand side
All of them could be as A would be an equilateral B,C,D would be irregular triangles and 3 would be an Isosceles triangle but if you had to go with one it would be A