Find the Missing measerment

Hey,

We had to find the missing measerment to the triangle. One side was 41mm and the other side was 5cm. Since we had to find in mm and cm i first converted 41mm to 4.1cm. Then i converted 5cm so 50mm. Now since we know the total perimeter of the triangle is 16 cm we can the add up both measurments we already have and subtract them from 16. I did 5+4.1=9.1, then i subtracted 9.1 from 16(16-9.1=6.9) So the missing side of the triangle is 6.9 cm and 69mm. So that is found out the missing measerment.