Answer:
D
Explanation:
let the 2 equal pieces be x then the other 3 are x + 2 , so summing gives
x + x + x + 2 + x + 2 + x + 2 = 31 , that is
5x + 6 = 31 ( subtract 6 from both sides )
5x = 25 ( divide both sides by 5 )
x = 5
Then the large pieces are x + 2 = 5 + 2 = 7 cm