Answer:
longest piece is 38 cm
medium piece is 26 cm
smallest piece is 19 cm
Explanation:
Let's assume longest piece is x cm
medium piece is y cm
smallest piece is z cm
The longest piece is twice as long as the shortest piece
so,

The other piece is 7 cm longer that the shortest piece
so,

A 83 -centimeter-long board is cut into 3 pieces
so,

now, we can plug these equations

now, we can solve for z


now, we can find x and y


so,
longest piece is 38 cm
medium piece is 26 cm
smallest piece is 19 cm